diff --git a/libgnucash/CMakeLists.txt b/libgnucash/CMakeLists.txt index a0ea47cf49..44dc1e5325 100644 --- a/libgnucash/CMakeLists.txt +++ b/libgnucash/CMakeLists.txt @@ -4,7 +4,6 @@ add_subdirectory (app-utils) add_subdirectory (backend) add_subdirectory (core-utils) -add_subdirectory (doc) add_subdirectory (engine) add_subdirectory (gnc-module) add_subdirectory (quotes) diff --git a/libgnucash/doc/CMakeLists.txt b/libgnucash/doc/CMakeLists.txt deleted file mode 100644 index f816f92d1b..0000000000 --- a/libgnucash/doc/CMakeLists.txt +++ /dev/null @@ -1,9 +0,0 @@ -set(doc_FILES - constderv.html - finderv.html - finutil.html - README - ) - -set_local_dist(doc_DIST_local CMakeLists.txt ${doc_FILES}) -set(doc_DIST ${doc_DIST_local} ${doc_design_DIST} PARENT_SCOPE) diff --git a/libgnucash/doc/README b/libgnucash/doc/README deleted file mode 100644 index ea663726e8..0000000000 --- a/libgnucash/doc/README +++ /dev/null @@ -1,4 +0,0 @@ - - -Please note that there is additional documentation in various -source subdirectories: for example, src/engine/*.txt diff --git a/libgnucash/doc/constderv.html b/libgnucash/doc/constderv.html deleted file mode 100644 index 0dc58bbaa6..0000000000 --- a/libgnucash/doc/constderv.html +++ /dev/null @@ -1,93 +0,0 @@ - - - -Financial Equations Documentation - - - -Return -
-

Constant Repayment to Principal Equations Derivation

-

In this loan, each total payment is different, with each succeeding payment -less than the preceding payment. Each payment is the total of the constant -amount to the principal plus the interest for the period. The constant payment -to the principal is computed as: - -

-        C = -PV / N
-
-

Where PV is the loan amount to be repaid in N payments (periods). Thus the -principal after the first payment is: - -

-    PV[1] = PV[0] + C = PV + C
-
- -

after the second payment, the principal is: - -

-    PV[2] = PV[1] + C = PV[0] + 2C
-
- -

In general, the remaining principal after n payments is: - -

-    PV[n] = PV[0] + nC = PV + nC
-
- -

If the effective interest per payment period is i, then the interest for the -first payment is: - -

-    I[1] = -i*PV[0]
-
- -

and for the second: - -

-    I[2] = -i * PV[1]
-
- -

and in general, for the n'th payment the interest is: - -

-    I[n] = -i * PV[n-1]
-         = -i * (PV + (n - 1)C)
-
- -

The total payment for any period, n, is: - -

-    P[n] = C + I[n]
-         = C - i * (PV + (n - 1)C)
-         = C(1 + i) - i * (PV + nC)
-
- -

The total interest paid to period n is: - -

-    T[n] = I[1] + I[2] + I[3] + ... + I[n]
-    T[n] = sum(j = 1 to n: I[j])
-    T[n] = sum(j = 1 to n: -i * (PV + (j-1)C))
-    T[n] = sum(j=1 to n: -i*PV) + sum(j=1 to n: iC) + sum(j=1 to n: -iCj)
-    T[n] = -i*n*PV + i*n*C - i*C*sum(j=1 to n:j)
-        sum(j=1 to n:j) = n(n+1)/2
-    T[n] = -i*n*(PV + C) - i*C*n(n+1)/2
-    T[n] = -i*n*(PV + (C*(n - 1)/2))
-
- -

Note: substituting for C = -PV/N, in the equations for PV[n], I[n], P[n], and T[n] -would give the following equations: - -

-    PV[n] = PV*(1 - n/N)
-    I[n]  = -i*PV*(1 + N - n)/N
-    P[n]  = -i*PV*(2 + N - n)/N
-    T[n]  = -i*n*PV*(2*N - n + 1)/(2*N)
-
- -

Using these equations for the calculations would eliminate the dependence -on C, but only if C is always defined as above and would eliminate the -possibility of another value for C. If the value of C was less than -PV/N -then a balloon payment would be due at the final payment and this is a possible -alternative for some people. diff --git a/libgnucash/doc/dia/components.dia b/libgnucash/doc/dia/components.dia deleted file mode 100644 index 6fec466415..0000000000 Binary files a/libgnucash/doc/dia/components.dia and /dev/null differ diff --git a/libgnucash/doc/dia/structures-alt.dia b/libgnucash/doc/dia/structures-alt.dia deleted file mode 100644 index 926ead4870..0000000000 Binary files a/libgnucash/doc/dia/structures-alt.dia and /dev/null differ diff --git a/libgnucash/doc/dia/structures.dia b/libgnucash/doc/dia/structures.dia deleted file mode 100644 index 26609e87d6..0000000000 Binary files a/libgnucash/doc/dia/structures.dia and /dev/null differ diff --git a/libgnucash/doc/finderv.html b/libgnucash/doc/finderv.html deleted file mode 100644 index f370d15eb2..0000000000 --- a/libgnucash/doc/finderv.html +++ /dev/null @@ -1,337 +0,0 @@ - - - -Financial Equations Documentation - - - -Return -


-
-
-
Basic Equation
-
Series Sum
-
-
-

Financial Equation Derivation

-

The financial equation is derived in the following manner: - -

Start with the basic equation to find the balance or Present Value, PV[1], after -one payment period. Note PV[1] is the Present Value after one payment and PV[0] -is the initial Present Value. PV[0] will be shortened to just PV. - -

The interest due at the end of the first payment period is the original present value, -PV, times the interest rate for the payment period plus the periodic payment times the -interest rate for beginning of period payments: - -

ID[1] = PV * i + X * PMT * i = (PV + X * PMT) * i - -

The Present Value after one payment is the original Present Value with the periodic -payment, PMT, and interest due, ID[1], added: - -

-   PV[1] = PV + (PMT + ID[1])
-   PV[1] = PV + (PMT + (PV + X * PMT) * i)
-   PV[1] = PV * (1 + i) + PMT * (1 + Xi)
-
- -

This equation works for all of the cash flow diagrams shown previously. The Present Value, -money received or paid, is modified by a payment made at the beginning of a payment -period and multiplied by the effective interest rate to compute the interest -due during the payment period. The interest due is then added to the payment -to obtain the amount to be added to the Present Value to compute the new Present Value. - -

For diagram 1): PV < 0, PMT == 0, PV[1] < 0 -
For diagram 2): PV == 0, PMT < 0, PV[1] < 0 -
For Diagram 3): PV > 0, PMT < 0, PV[1] >= 0 or PV[1] <= 0 -
For Diagram 4): PV < 0, PMT > 0, PV[1] <= 0 or PV[1] >= 0 - -

X may be 0 or 1 for any diagram. - -

For the standard loan, PV is the money borrowed, PMT is the periodic payment to repay -the loan, i is the effective interest rate agreed upon and FV is the residual loan amount -after the agreed upon number of periodic payment periods. If the loan is fully paid off -by the periodic payments, FV is zero, 0. If the loan is not completely paid off after the -agreed upon number of payments, a balloon payment is necessary to completely pay off the loan. -FV is then the amount of the needed balloon payment. For a loan in which the borrower pays -only enough to repay the interest due during a payment period, interest only loan, the -balloon payment is equal to the negative of PV. - -

To calculate the Present Value after the second payment period, the above calculation -is applied iteratively to PV[1] to obtain PV[2]. In fact to calculate the Present Value -after any payment period, PV[n], the above equation is applied iteratively to PV[n-1] -as shown below. - -

-   PV[2] = PV[1] + (PMT + (PV[1] + X * PMT) * i)
-         = PV[1] * (1 + i) + PMT * (1 + iX)
-         = (PV * (1 + i) + PMT * (1 + iX)) * (1 + i) + PMT * (1 + iX)
-         = PV * (1 + i)^2 + PMT * (1 + iX) * (1 + i)
-                          + PMT * (1 + iX)
-
- -

Similarly, PV[3] is computed from PV[2] as: - -

-   PV[3] = PV[2] + (PMT + (PV[2] + X * PMT) * i)
-         = PV[2] * (1 + i) + PMT * (1 + iX)
-         = (PV * (1 + i)^2 + PMT * (1 + iX) * (1 + i)
-                           + PMT * (1+  iX)) * (1 + i)
-                           + PMT * (1+  iX)
-         = PV * (1 + i)^3 + PMT * (1 + iX) * (1 + i)^2
-                          + PMT * (1 + iX) * (1 + i)
-                          + PMT * (1 + iX)
-
- -

And for the n'th payment, PV[n] is computed from PV[n-1] as: - -

-   PV[n] = PV[n-1] + (PMT + (PV[n-1] + X * PMT) * i)
-   PV[n] = PV * (1 + i)^n + PMT * (1 + iX) * (1 + i)^(n-1)
-                          + PMT * (1 + iX) * (1 + i)^(n-2) +
-                          .
-                          .
-                          .
-                          + PMT * (1 + iX) * (1 + i)
-                          + PMT * (1 + iX)
-   PV[n] = PV * (1 + i)^n + PMT * (1 + iX) * [(1 + i)^(n-1) + ... + (1 + i) + 1]
-
- -

The formula for PV[n] can be proven using mathematical induction. - - -

Basic Financial Equation

-

As shown above, the basic financial transaction equation is simply: - -

-   PV[n] = PV[n-1] + (PMT + (PV[n-1] + X * PMT) * i)
-         = PV[n-1] * (1 + i) + PMT * (1 + iX)
-    for: n >= 1
-
- -

relating the Present Value after n payments, PV[n] to the previous Present Value, PV[n-1]. - - - -


- -

Series Sum

-

The sum of the finite series: - -

1 + k + (k^2) + (k^3) + ... + (k^n) = (1-k^(n+1))/(1-k) - -

as can be seen by the following. Let S(n) be the series sum. Then - -

S(n) - k * S(n) = 1 - k^(n+1) - -

and solving for S(n): - -

S(n) = (1-k^(n+1))/(1-k) = 1 + k + (k^2) + (k^3) + ... + (k^n) - - -


- -

Using this in the equation above for PV[n], we have: - -

-   PV[n] = PV * (1 + i)^n + PMT * (1 + iX) * [(1 + i)^(n-1) + ... + (1 + i) + 1]
-         = PV * (1 + i)^n + PMT * (1 + iX) * [1 - (1 + i)^n]/[1 - (1 + i)]
-         = PV * (1 + i)^n + PMT * (1 + iX) * [1 - (1 + i)^n]/[-i]
-         = PV * (1 + i)^n + PMT * (1 + iX) * [(1 + i)^n - 1]/i
-
- -

or: - -

-   PV * (1 + i)^n + PMT * [(1 + i)^n - 1]/i - PV[n] = 0
-
- -

If after n payments, the remaining balance is repaid as a lump sum, the lump sum -is known as the Future Value, FV[n]. Since FV[n] is negative if paid and positive -if received, FV[n] is the negative of PV[n]. - -

Setting: FV[n] = -PV[n] - -

Since n is assumed to be the last payment, FV[n] will be shortened to simply -FV for the last payment period. - -

-   PV*(1 + i)^n + PMT*(1 + iX)*[(1 + i)^n - 1]/i + FV = 0
-
- -

Up to this point, we have said nothing about the value of PMT. PMT can be any value mutually -agreed upon by the lender and the borrower. From the equation for PV[1]: - -

-   PV[1] = PV + (PMT + (PV + X * PMT) * i),
-
- -

Several things can be said about PMT. - -

    -
  1. If PMT = -(PV * i), and X = 0 (end of period payments): - -

    The payment is exactly equal to the interest due and PV[1] = PV. In this case, the borrower -must make larger future payments to reduce the balance due, or make a single payment, after -some agreed upon number of payments, with PMT = -PV to completely pay off the loan. This is -an interest only payment with a balloon payment at the end. - -

  2. If |PMT| < |PV * i|, and X = 0 and PV > 0 -

    The payment is insufficient to cover even the interest charged and the balance due grows - -

  3. If |PMT| > |PV * i|, and X = 0 and PV > 0 -

    The payment is sufficient to cover the interest charged with a residual amount to be -applied to reduce the balance due. The larger the residual amount, the faster the loan is -repaid. For most mortgages or other loans made today, the lender and borrower agree upon -a certain number of repayment periods and the interest to be charged per payment period. -The interest may be multiplied by 12 and stated as an annual interest rate. Then the -lender and borrower want to compute a periodic payment, PMT, which will reduce the balance -due to zero after the agreed upon number of payments have been made. If N is the agreed -upon number of periodic payments, then we want to use: - -

    -      PV * (1 + i)^N + PMT*(1 +iX)*[(1 + i)^N - 1]/i + FV = 0
    -
    - -

    with FV = 0 to compute PMT: - -

    -      PMT = -[PV * i * (1 + i)^(N - X)]/[(1 + i)^N - 1]
    -
    - -

    The value of PMT computed will reduce the balance due to zero after N periodic payments. -Note that this is strictly true only if PMT is not rounded to the nearest cent as is the -usual case since it is hard to pay fractional cents. Rounding PMT to the nearest cent has -an effect on the FV after N payments. If PMT is rounded up, then the final Nth payment -will be smaller than PMT since the periodic PMTs have paid down the principal faster than -the exact solution. If PMT is rounded down, then the final Nth payment will be larger than -the periodic PMTs since the periodic PMTs have paid down the principal slower than the -exact solution. -

- - - -

With a simple alegebraic re-arrangement, The financial Equation becomes: - -

-  2) [PV + PMT*(1 + iX)/i][(1 + i)^n - 1] + PV + FV = 0
-
- -

or - -

-  3) (PV + C)*A + PV + FV = 0
-
- -

where: -

-  4) A = (1 + i)^n - 1
-
-  5) B = (1 + iX)/i
-
-  6) C = PMT*B
-
- -

The form of equation 3) simplifies the calculation procedure for all five -variables, which are readily solved as follows: - -

-  7) n = ln[(C - FV)/(C + PV)]/ln((1 + i)
-
-  8) PV = -[FV + A*C]/(A + 1)
-
-  9) PMT = -[FV + PV*(A + 1)]/[A*B]
-
- 10) FV = -[PV + A*(PV + C)]
-
- -

Equations 4), 5) and 6) are computed by the functions in the "fin.exp" utility: - -
_A -
_B -
_C - -

respectively. Equations 7), 8), 9) and 10) are computed by functions: - -
_N -
_PV -
_PMT -
_FV - -

respectively. - -

The solution for interest is broken into two cases: - -

    -
  1. PMT == 0 -

    Equation 3) can be solved exactly for i: - -

    -       i = [FV/PV]^(1/n) - 1
    -
    - -
  2. PMT != 0 -

    Since equation 3) cannot be solved explicitly for i in this case, an -iterative technique must be employed. Newton's method, using exact -expressions for the function of i and its derivative, are employed. The -expressions are: - -

    - 12) i[k+1] = i[k] - f(i[k])/f'(i[k])
    -       where: i[k+1] == (k+1)st iteration of i
    -              i[k]   == kth iteration of i
    -       and:
    -
    - 13) f(i) = A*(PV+C) + PV + FV
    -
    - 14) f'(i) = n*D*(PV+C) - (A*C)/i
    -
    - 15) D = (1 + i)^(n-1) = (A+1)/(1+i)
    -
    - -

    To start the iterative solution for i, an initial guess must be made -for the value of i. The closer this guess is to the actual value, -the fewer iterations will have to be made, and the greater the -probability that the required solution will be obtained. The initial -guess for i is obtained as follows: - -

      -
    1. PV case, PMT*FV >= 0 - -
      -                | n*PMT + PV + FV |
      - 16)     i[0] = | ----------------|
      -                |      n*PV       |
      -
      -              = abs[(n*PMT + PV + FV)/(n*PV)]
      -
      - -
    2. FV case, PMT*FV < 0 -
        -
      1. PV != 0 - -
        -                    |      FV - n*PMT           |
        - 17)         i[0] = |---------------------------|
        -                    | 3*[PMT*(n-1)^2 + PV - FV] |
        -
        -                  = abs[(FV-n*PMT)/(3*(PMT*(n-1)^2+PV-FV))]
        -
        - - -
      2. PV == 0 - -
        -                    |      FV + n*PMT           |
        - 18)         i[0] = |---------------------------|
        -                    | 3*[PMT*(n-1)^2 + PV - FV] |
        -
        -                  = abs[(FV+n*PMT)/(3*(PMT*(n-1)^2+PV-FV))]
        -
        - -
      -
    -
-
-Return - diff --git a/libgnucash/doc/finutil.html b/libgnucash/doc/finutil.html deleted file mode 100644 index ca8687e3bf..0000000000 --- a/libgnucash/doc/finutil.html +++ /dev/null @@ -1,2278 +0,0 @@ - - - - -Financial Utility Documentation - - - -
-

Financial Transaction Utility

- -
-
-
Financial Calculator
-
Time Value of Money
-
Simple Interest
-
Compound Interest
-
Periodic Payments
-
Financial Transactions
-
Standard Financial Conventions
-
Cash Flow Diagrams
-
Appreciation
-
Annuity
-
Amortization
-
Annuity
-
Interest
-
Compounding Frequency
-
Payment Frequency
-
NAR to EIR for Discrete Interest Periods
-
NAR to EIR for Continuous Interest
-
Normal CF/PF Values
-
EIR to NAR for Discrete Interest Periods
-
EIR to NAR for Continuous Compounding
-
Financial Equation
-
Financial Equation Derivation
-
Amortization Schedules
-
Effective and Initial Payment Dates
-
Effective Present Value
-
Iterative Amortization Schedule
-
Annual Summary
-
Final Payment Calculation
-
Amortization Cases
-
-
Constant Repayment to Principal, Original Data
-
Constant Repayment to Principal, Delayed Repayment
-
Original Data Schedule
-
Recomputed Final Payment
-
Recomputed Periodic Payment
-
Recomputed Term
-
-
Amortization Schedule Display
-
Financial Calculator Usage
-
Calculator Commands
-
Calculator Input
-
Calculator Functions
-
User Defined Variables
-
Rounding
-
Examples
-
Simple Interest
-
Compound Interest
-
Periodic Payment
-
Conventional Mortgage
-
Final Payment
-
Conventional Mortgage Amortization Schedule - Annual Summary
-
Conventional Mortgage Amortization Schedule - Periodic Payment Schedule
-
Conventional Mortgage Amortization Schedule - Variable Advanced Payments
-
Conventional Mortgage Amortization Schedule - Constant Advanced Payments
-
Balloon Payment
-
Canadian Mortgage
-
European Mortgage
-
Bi-weekly Savings
-
Present Value - Annuity Due
-
Effective Rate - 365/360 Basis
-
Mortgage with "Points"
-
Equivalent Payments
-
Perpetuity - Continuous Compounding
-
Investment Return
-
Retirement Investment
-
Property Values
-
College Expenses
-
Certificate of Deposit, Annual Percentage Yield
-
References
-
-
- -

Financial Calculator

-

Financial Calculator - - - - -

This is a complete financial computation utility to solve for the five -standard financial values: n, %i, PV, PMT and FV -

- -

In addition, four additional parameters may be specified: -

    -
  1. Compounding Frequency per year, CF. The number of times the interest is compounded -during the year. The default is 12. The compounding frequency per year may be -different from the Payment Frequency per year - -
  2. Payment Frequency per year, PF. The number of payments made in a year. Default is 12. - -
  3. Discrete or continuous compounding, disc. The default is discrete compounding. - -
  4. Payments may be at the beginning or end of the payment period, beg. The default is for -payments to be made at the end of the payment period. -
- -

When an amortization schedule is desired, the financial transaction Effective Date, ED, -and Initial Payment Date, IP, must also be entered. - -

Canadian and European style mortgages can be handled in a simple, -straight-forward manner. Standard financial sign conventions are used: - -


-

"Money paid out is Negative, Money received is Positive" -


- - -

Time Value of Money

-

If you borrow money, you can expect to pay rent or interest for its use; -conversely you expect to receive rent interest on money you loan or invest. -When you rent property, equipment, etc., rental payments are normal; this -is also true when renting or borrowing money. Therefore, money is -considered to have a "time value". Money available now, has a greater value -than money available at some future date because of its rental value or the -interest that it can produce during the intervening period. - - -

Simple Interest

-

If you loaned $800 to a friend with an agreement that at the end of one -year he would would repay you $896, the "time value" you placed on your -$800 (principal) was $96 (interest) for the one year period (term) of the -loan. This relationship of principal, interest, and time (term) is most -frequently expressed as an Annual Percentage Rate (APR). In this case the -APR was 12.0% [(96/800)*100]. This example illustrates the four basic -factors involved in a simple interest case. The time period (one year), -rate (12.0% APR), present value of the principal ($800) and the future -value of the principal including interest ($896). - - -

Compound Interest

-

In many cases the interest charge is computed periodically during the term -of the agreement. For example, money left in a savings account earns -interest that is periodically added to the principal and in turn earns -additional interest during succeeding periods. The accumulation of interest -during the investment period represents compound interest. If the loan -agreement you made with your friend had specified a "compound interest -rate" of 12% (compounded monthly) the $800 principal would have earned -$101.46 interest for the one year period. The value of the original $800 -would be increased by 1% the first month to $808 which in turn would be -increased by 1% to 816.08 the second month, reaching a future value of -$901.46 after the twelfth iteration. The monthly compounding of the nominal -annual rate (NAR) of 12% produces an effective Annual Percentage Rate (APR) -of 12.683% [(101.46/800)*100]. Interest may be compounded at any regular -interval; annually, semiannually, monthly, weekly, daily, even continuously -(a specification in some financial models). - - -

Periodic Payments

-

When money is loaned for longer periods of time, it is customary for the -agreement to require the borrower to make periodic payments to the lender -during the term of the loan. The payments may be only large enough to repay -the interest, with the principal due at the end of the loan period (an -interest only loan), or large enough to fully repay both the interest and -principal during the term of the loan (a fully amoritized loan). Many loans -fall somewhere between, with payments that do not fully cover repayment of -both the principal and interest. These loans require a larger final payment -(balloon) to complete their amortization. Payments may occur at the -beginning or end of a payment period. If you and your friend had agreed on -monthly repayment of the $800 loan at 12% NAR compounded monthly, twelve -payments of $71.08 for a total of $852.96 would be required to amortize the -loan. The $101.46 interest from the annual plan is more than the $52.96 -under the monthly plan because under the monthly plan your friend would not -have had the use of $800 for a full year. - - -

Financial Transactions

-

The above paragraphs introduce the basic factors that govern most -financial transactions; the time period, interest rate, present value, -payments and the future value. In addition, certain conventions must be -adhered to: the interest rate must be relative to the compounding frequency -and payment periods, and the term must be expressed as the total number of -payments (or compounding periods if there are no payments). Loans, leases, -mortgages, annuities, savings plans, appreciation, and compound growth are -among the many financial problems that can be defined in these terms. Some -transactions do not involve payments, but all of the other factors play a -part in "time value of money" transactions. When any one of the five (four -- if no payments are involved) factors is unknown, it can be derived from -formulas using the known factors. - - -

Standard Financial Conventions

-

The Standard Financial Conventions are: - -

- - -

Cash Flow Diagrams

-

If payments are a part of the transaction, the number of payments must -equal the number of periods (n). - -

Payments may be represented as occurring at the end or beginning of the -periods. - -

Diagram to visualize the positive and negative cash flows (cash flow -diagrams): - -

Amounts shown above the line are positive, received, and amounts shown below the -line are negative, paid out. - -


- -

Appreciation

-
Appreciation -
Depreciation -
Compound Growth -
Savings Account -
-                                                                A FV*
-          1   2   3   4   .   .   .   .   .   .   .   .   .   n |
- Period +---+---+---+---+---+---+---+---+---+---+---+---+---+---+
-        |
-        V
-        PV
-
- - - - -
- -

Annuity (series of payments)

-
Annuity (series of payments) -
Pension Fund -
Savings Plan -
Sinking Fund - -
-     PV = 0                                                     A
-                                                                |
- Period +---+---+---+---+---+---+---+---+---+---+---+---+---+---+
-        | 1 | 2 | 3 | 4 | . | . | . | . | . | . | . | . | . | n
-        V   V   V   V   V   V   V   V   V   V   V   V   V   V
-       PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT
-
- - - - -
- -

Amortization

-
Direct Reduction Loan -
Mortgage (fully amortized) - -
-     PV ^
-        |                                                      FV=0
- Period +---+---+---+---+---+---+---+---+---+---+---+---+---+---+
-          1 | 2 | 3 | 4 | . | . | . | . | . | . | . | . | . | n |
-            V   V   V   V   V   V   V   V   V   V   V   V   V   V
-           PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT
-
- - - -
- -

Annuity

-
Annuity -
Lease (with buy back or residual)* -
Loan or Mortgage (with balloon)* -
-                                                                A FV*
-           PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT PMT  | +
-            A   A   A   A   A   A   A   A   A   A   A   A   A   A PMT
-          1 | 2 | 3 | 4 | . | . | . | . | . | . | . | . | . | n |
- Period +---+---+---+---+---+---+---+---+---+---+---+---+---+---+
-        |
-        V
-        PV
-
- - - -
- -

Interest

-

Before discussing the financial equation, we will discuss interest. Most -financial transactions utilize a nominal interest rate, NAR, i.e., the interest -rate per year. The NAR must be converted to the interest rate per payment -period and the compounding accounted for before it can be used in computing -an interest payment. After this conversion process, the interest used is the -effective interest rate, EIR. In converting NAR to EIR, there are two concepts -to discuss first, the Compounding Frequency and the Payment Frequency and -whether the interest is compounded in discrete intervals or continuously. - - -

Compounding Frequency

-

The compounding Frequency, CF, is simply the number of times per year, the -monies in the financial transaction are compounded. In the U.S., monies -are usually compounded daily on bank deposits, and monthly on loans. Sometimes -long term deposits are compounded quarterly or weekly. - - -

Payment Frequency

-

The Payment Frequency, PF, is simply how often during a year payments are -made in the transaction. Payments are usually scheduled on a regular basis -and can be made at the beginning or end of the payment period. If made at -the beginning of the payment period, interest must be applied to the payment -as well as any previous money paid or money still owed. - - -

Normal CF/PF Values

-

Normal values for CF and PF are: -

- -

The Compounding Frequency per year, CF, need not be identical to the -Payment Frequency per year, PF. Also, -Interest may be compounded in either discrete intervals or continuously -compounded and payments may be made at the beginning of the payment period or at the -end of the payment period. - -

CF and PF are defaulted to 12. The default is for discrete interest intervals -and payments are defaulted to the end of the payment period. - -

When a solution for n, PV, PMT or FV is required, the nominal interest -rate, i, must first be converted to the effective interest rate per payment -period. This rate, ieff, is then used to compute the selected variable. To -convert i to ieff, the following expressions are used: - - -

NAR to EIR for Discrete Interest Periods

-

To convert NAR to EIR for discrete interest periods: - -

ieff = (1 + i/CF)^(CF/PF) - 1 - - -

NAR to EIR for Continuous Compounding

-

to convert NAR to EIR for Continuous Compounding: - -

ieff = e^(i/PF) - 1 = exp(i/PF) - 1 - -

When interest is computed, the computation produces the effective interest -rate, ieff. This value must then be converted to the nominal interest rate. -Function _I in the "fin.exp" utility returns the nominal interest -rate NOT the effective interest rate. ieff is converted to i using the following expressions: - - -

EIR to NAR for Discrete Interest Periods

-

To convert EIR to NAR for discrete interest periods: - -

i = CF*([(1+ieff)^(PF/CF) - 1) - - -

EIR to NAR for Continuous Compounding

-

To convert EIR to NAR for continuous compounding: - -

i = ln((1+ieff)^PF) - - - - - - -

Financial Equation

-

NOTE: in the equations below for the financial transaction, all interest rates -are the effective interest rate, ieff. The symbol will be shortned to just i. - -

The financial equation used to inter-relate n,i,PV,PMT and FV is: - -

1) PV*(1 + i)^n + PMT*(1 + iX)*[(1+i)^n - 1]/i + FV = 0 - -

-   Where: X   == 0 for end of period payments, and
-          X   == 1 for beginning of period payments
-          n   == number of payment periods
-          i   == effective interest rate for payment period
-          PV  == Present Value
-          PMT == periodic payment
-          FV  == Future Value
-
- - - -

Financial Equation Derivation

-

The derivation of the financial equation is contained in the -Financial Equations -section. - - - - - -

Amortization Schedules.

- - -

Effective and Initial Payment Dates

-

Financial Transactions have an effective Date, ED, and an Initial Payment -Date, IP. ED may or may not be the same as IP, but IP is always the same -or later than ED. Most financial transaction calculators assume that -IP is equal to ED for beginning of period payments or at the end of the -first payment period for end of period payments. - -

This is not always true. IP may be delayed for financial reasons such as cash -flow or accounting calendar. The subsequent payments then follow the -agreed upon periodicity. - - -

Effective Present Value

-

Since money has a time value, the "delayed" IP -must be accounted for. Computing an "Effective PV", pve, is one means of -handling a delayed IP. - -

If - -

-ED_jdn == the Julian Day Number of ED, and
-IP_jdn == the Julian Day Number of IP
-
- -

pve is computed as: - -

-   pve = pv*(1 + i)^(s*PF/d*CF)
-
-   Where: d = length of the payment period in days, and
-          s = IP_jdn - ED_jdn - d*(1 - X)
-
- - -

Iterative Amortization Schedule

-

Computing an amortization Schedule for a given financial transaction is -simply applying the basic equation iteratively for each payment period: - -

-   PV[n] = PV[n-1] + (PMT + (PV[n-1] + X * PMT) * i)
-         = PV[n-1] * (1 + i) + PMT * (1 + iX)
-    for n >= 1
-
- -

At the end of each iteration, PV[n] is rounded to the nearest cent. For -each payment period, the interest due may be computed separately as: - -

-   ID[n] = (PV[n-1] + X * PMT) * i
-
- -

and rounded to the nearest cent. PV[n] then becomes: - -

-   PV[n] = PV[n-1] + PMT + ID[n]
-
- - -

Annual Summary

-

For those cases where a yearly summary only is desired, it is not necessary -to compute each transaction for each payment period, rather the PV may be -be computed for the beginning of each year, PV[yr], and the FV computed for -the end of the year, FV[yr]. The interest paid during the year is the computed as: - -

-   ID[yr] = (NP * PMT) + PV[yr] + FV[yr]
-    where: NP == number of payments during year
-              == PF for a full year of payments
-
- - -

Final Payment Calculation

-

Since the final payment may not be equal to the periodic payment, the final -payment must be computed separately as follows. Two derivations are given below -for the final payment equation. Both derivations are given below since one or -the other may be clearer to some readers. Both derivations are essentially -the same, they just have different starting points. The first is the fastest to derive. - -

Note, for the purposes of computing an amortization table, the number of periodic -payments is assumed to be an integral value. For most cases this is true, the two -principles in any transaction usually agree upon a certain term or number of periodic -payments. In some calculations, however, this may not hold. In all of the calculations -below, n is assumed integral and in the gnucash implementation, the following calculation -is performed to assure this fact: - -

-    n = int(n)
-
- -
    -
  1. final_pmt == final payment @ payment n -

    From the basic financial equation derived above: - -

    -       PV[n] = PV[n-1]*(1 + i) + final_pmt * (1 + iX), i == effective interest rate
    -
    - -

    solving for final_pmt, we have: -

    NOTE: FV[n] = -PV[n], for any n - -

    -       final_pmt * (1 + iX) = PV[n] - PV[n-1]*(1 + i)
    -                            = FV[n-1]*(1 + i) - FV[n]
    -       final_pmt = FV[n-1]*(1+i)/(1 + iX) - FV[n]/(1 + iX)
    -
    -       final_pmt = FV[n-1]*(1 + i) - FV[n], for X == 0, end of period payments
    -                 = FV[n-1] - FV[n]/(1 + i), for X == 1, beginning of period payments
    -
    - -
  2. final_pmt == final payment @ payment n - -
    -       i[n] == interest due @ payment n
    -       i[n] = (PV[n-1] + X * final_pmt) * i, i == effective interest rate
    -            = (X * final_pmt - FV[n]) * i
    -
    - -

    Now the final payment is the sum of the interest due, plus the present value -at the next to last payment plus any residual future value after the last payment: - -

    -       final_pmt = -i[n] - PV[n-1] - FV[n]
    -                 = FV[n-1] - i[n] - FV[n]
    -                 = FV[n-1] - (X *final_pmt - FV[n-1])*i - FV[n]
    -                 = FV[n-1]*(1 + i) - X*final_pmt*i - FV[n]
    -
    - -

    solving for final_pmt: - -

    -       final_pmt*(1 + iX) = FV[n-1]*(1 + i) - FV[n]
    -       final_pmt = FV[n-1]*(1 + i)/(1 + iX) - FV[n]/(1 + iX)
    -
    -       final_pmt = FV[n-1]*(1 + i) - FV[n], for X == 0, end of period payments
    -                 = FV[n-1] - FV[n]/(1 + i), for X == 1, beginning of period payments
    -
    -
- - - - -

Amortization Cases

- -

The amortization schedule is computed for six different situations: - -

    - -

    Constant Repayment to Principal, Original Data

    -
  1. In a constant repayment to principal loan, each payment varies. A constant amount -is applied to the principal for each payment, usually equal to the originating present value -divided by the number of repayment periods, and the interest for the payment period is -added to the constant principal payment. The derivation of the equation for this type -is contained in the Constant Repayment Equations section. This -case computes the amortization schedule with the original loan data and a constant repayment -to principal. - - -

    Constant Repayment to Principal, Delayed Repayment

    -
  2. In a constant repayment to principal loan, each payment varies. A constant amount -is applied to the principal for each payment, usually equal to the originating present value -divided by the number of repayment periods, and the interest for the payment period is -added to the constant principal payment. The derivation of the equation for this type -is contained in the Constant Repayment Equations section. This -case computes the amortization schedule with the delayed loan data and a constant repayment -to principal. - - -

    Original Data Schedule

    -
  3. The original financial data is used. This ignores any possible agjustment to -the Present value due to any delay in the initial payment. This is quite -common in mortgages where end of period payments are used and the first -payment is scheduled for the end of the first whole period, i.e., any -partial payment period from ED to the beginning of the next payment period -is ignored. - - -

    Recomputed Final Payment

    -
  4. The original periodic payment is used, the Present Value is adjusted for the -delayed Initial Payment. The total number of payments remains the same. The -final payment is adjusted to bring the balance into agreement with the -agreed upon final Future Value. - - -

    Recomputed Periodic Payment

    -
  5. A new periodic payment is computed based upon the adjusted Present Value, the -originally agreed upon number of total payments and the agreed upon Future Value. -The new periodic payments are computed to minimize the final payment in accordance -with the Future Value after the last payment. - - -

    Recomputed Term

    -
  6. The original periodic payment is retained and a new number of total payments is computed -based upon the adjusted Present Value and the agreed upon Future Value. -
- - -

Amortization Schedule Display

-

The amortization schedule may be computed and displayed in three manners: - -

    -
  1. The payment#, interest paid, principal paid and remaining PV for each payment period -are computed and displayed. -

    At the end of each year a summary is computed and displayed -and the total interest paid is displayed at the end. - -

  2. A summary is computed and displayed for each year. The interest paid during the -year is computed and displayed as well as the remaining balance at years end. -

    The total interest paid is displayed at the end. - -

  3. An amortization schedule is computed and displayed for a common method of -advanced payment of principal. -

    In this amortization schedule, the principal for the -next payment is computed and added into the current payment. This method will -cut the number of total payments in half and will cut the interest paid almost -in half. -

    For mortgages, this method of prepayment has the advantage of keeping -the total payments small during the initial payment periods -The payments grow until the last payment period when presumably the borrower -can afford larger payments. -

- - -

NOTE: For Payment Frequencies, PF, semi-monthly or less, i.e., PF == 12 or PF == 24, -a 360 day calendar year and 30 day month are used. For Payment Frequencies, PF, -greater than semi-monthly, PF > 24, the actual number of days per year and per payment -period are used. The actual values are computed using the built-in 'jdn' function - - - -

Financial Calculator Usage

-

the Financial Calculator is run as a QTAwk utility. If input is to be interactive and -from the keyboard, do not specify any input files on the command line. The financial -calcutlator reads all input from the standard input file. The calculator is started -as: - -

-QTAwk -f fin.exp
-
- -

The calculator will clear the display screen and display a two screen help: - -

-Financial Calculator
-Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-To compute Loan Quantities:
-N ==> to compute # payment periods from i, pv, pmt, fv
-_N(i,pv,pmt,fv,CF,PF,disc,bep) ==> to compute # payment periods
-I ==> to compute nominal interest rate from n, pv, pmt, fv, CF, PF, disc, bep
-_I(n,pv,pmt,fv,CF,PF,disc,bep) ==> to compute interest
-PV ==> to compute Present Value from n, i, pmt, fv, CF, PF, disc, bep
-_PV(n,i,pmt,fv) ==> to compute Present Value
-PMT ==> to compute Payment from n, i, pv, fv, CF, PF, disc, bep
-_PMT(n,i,pv,fv,CF,PF,disc,bep) ==> to compute Payment
-FV ==> to compute Future Value from n, i, pv, pmt, CF, PF, disc, bep
-_FV(n,i,pv,pmt,CF,PF,disc,bep) ==> to compute Future Value
-Press Any Key to Continue
-
- -

The first screen displays the calculator commands which are available. Press any key -and a second screen displays the variables defined by the calculator and which must be -set by the user to use the financial calculator functions. - -

-[Aa](mort)? to Compute Amortization Schedule
-[Cc](ls)? to Clear Screen
-[Dd](efault)? to Re-Initialize
-[Hh](elp) to Display This Help
-[Qq](uit)? to Quit
-[Ss](tatus)? to Display Status of Computations
-[Uu](ser) Display User Defined Variables
-
-Variables to set:
-n    == number of periodic payments
-i    == interest per compouding interval
-pv   == present value
-pmt  == periodic payment
-fv   == future value
-disc == TRUE/FALSE == discrete/continuous compounding
-bep  == TRUE/FALSE == beginning of period/end of period payments
-CF   == compounding frequency per year
-PF   == payment frequency per year
-
-ED   == effective date of transaction, mm/dd/yyyy
-IP   == initial payment date of transaction, mm/dd/yyyy
-
- - -

Calculator Commands

-

The financial calculator commands available are listed above and below. - -

Note that the first letter of the command is all that is necessary to activate the -desired function. - -

    -
  1. [Aa](mort)? to Compute Amortization Schedule -
    After all financial variables have been defined as well as the transaction dates, -the amortization schedule can be computed for all financial transactions in which -one would make sense. -
  2. [Cc](ls)? to Clear Screen -
    This command clears the screen and displays the copyright. -
  3. [Dd](efault)? to Re-Initialize -
    This command re-initializes all calculator variables to their start-up values. -
  4. [Hh](elp) to Display This Help -
    This command is used to display the start-up help screens at any time. -
  5. [Qq](uit)? to Quit -
    When the calculator is used interactively from the keyboard, this command allows -the user to terminate the calculator session. -
  6. [Ss](tatus)? to Display Status of Computations -
    This command displays the status of the calculator variables. A typical status display -would be: - -
    -Financial Calculator
    -Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved
    -Current Financial Calculator Status:
    -Compounding Frequency: (CF) 12
    -Payment     Frequency: (PF) 12
    -Compounding: Discrete (disc = TRUE)
    -Payments: End of Period (bep = FALSE)
    -Number of Payment Periods (n): 360              (Years: 30)
    -Nominal Annual Interest Rate (i): 7.25
    -  Effective Interest Rate Per Payment Period: 0.00604167
    -Present Value (pv): 233,350.00
    -Periodic Payment (pmt): -1,591.86
    -Future Value (fv): 0.00
    -Effective       Date: Tue Jun 04 00:00:00 1996(2450239)
    -Initial Payment Date: Thu Aug 01 00:00:00 1996(2450297)
    -<>
    -
    -
  7. [Uu](ser) Display User Defined Variables -
    If any variables have been defined by the user, this command displays their names and -values. -
- - -

Calculator Input

-

The calculator displays an input prompt whenever it is waiting for input -from the keyboard. The input prompt is simply <>. The desired -input is typed at the keyboard and the enter key pressed. The result of calculating the -value of the input line is then displayed by the calculator. For example, if the user wanted -to set the value of the nominal interest in the calculator to 6.25, the following line would be -input to the calculator: - -

i=6.25. - -

A semi-colon at the end of the input is optional. -The line as seen on the display with the calculator input prompt would be: - -

-<>i = 6.25
-    6.25
-
- -

Note that the calculator displays the value of the result, 6.25 in this case. - -

The calculator is controlled by setting the calculator variables to the desired values -and "executing" the calculator functions to derive the values for the unknown -variables. For example, for a conventional home mortgage for $233,350.00 with a thirty year -term, nominal annual rate of 7.25%, n, i, pv and fv are known: - -

-n == 360 == 12 * 30
-i == 7.25
-pv= 233350
-fv = 0
-
- -

The payments to completely pay off the mortgage with the 360 periodic payments is desired. -To compute the desired periodic payment value, the PMT function is used. Since the -function has no defined arguments, in invoking the function no arguments are specified. The -complete session to input the desired values and calculate the periodic payment value would -appear as: - -

-<>n=30*12
-        360
-<>i=7.25
-        7.25
-<>pv=233350
-        233,350
-<>PMT
-        -1,591.86
-
- -

Note that the input may contain computations, n=30*12. In addition, any QTAwk -built-in function may be specified and any functions defined in the financial calculator. -This can be handy for computing intermediate values or other results from the results of -the calculator. - -

Note that the output of the PMT function is rounded to the nearest cent. Over the -thirty year term of the payback, the rounding will affect the last payment. To determine -the balance due, fv, after 359 payment have been made, decrement n by 1 and compute the -future value: - -

-<>n-=1
-        359
-<>FV
-        -1,580.20
-<>n+=1
-        360
-<>FV
-        2.12
-<>
-
- -

The future value after 359 payments is less than the periodic payment and a full final payment -will overpay the loan. The final FV computation with n restored to 360 shows an overpayment -of 2.12. - - -

Calculator Functions

-

The calculator functions: - -

-N
-I
-PV
-PMT
-FV
-
- -

can be used to calculate the variable with the corresponding lower case name, using the -values of the other four calculator variables which have already been set. In addition, the -calculator functions: - -

-_N(i,pv,pmt,fv,CF,PF,disc,bep)
-_I(n,pv,pmt,fv,CF,PF,disc,bep)
-_PV(n,i,pmt,fv,CF,PF,disc,bep)
-_PMT(n,i,pv,fv,CF,PF,disc,bep)
-_FV(n,i,pv,pmt,CF,PF,disc,bep)
-
- -

can be used to compute the value of the corresponding quantity for any specified value -of the input arguments. - -

There are three differences between the functions N, I, PV, PMT, FV and the -functions -_N(i,pv,pmt,fv,CF,PF,disc,bep), _I(n,pv,pmt,fv,CF,PF,disc,bep), _PV(n,i,pmt,fv,CF,PF,disc,bep), -_PMT(n,i,pv,fv,CF,PF,disc,bep), _FV(n,i,pv,pmt,CF,PF,disc,bep). -

    -
  1. The first set of functions take no arguments and -use the calculator variables, n, i, pv, pmt, fv, CF, PF, disc -and bep to compute the desired value. The second set of functions use the values passed in -the function arguments. The first set of functions call the second set with the necessary -arguments. -
  2. The first set of functions round the computed value returned by the call to the second set -of functions to the nearest cent. The second set of functions perform no rounding. -
  3. The first set of functions set the calculator variables with the corresponding lower case name -to the value computed. The second set of functions set no global variable values. -
- - -

User Defined Variables

-

User defined variables may be defined and their values set to a desired qunatity. For example, -to save computation results before re-initializing the calculator to obtain other results. If -the user desired to compare the periodic payments necessary to fully pay the conventional -mortgage cited above, the payment computed above could be saved in the variable -end_pmt, the payments set to beginning of period payments and the new payment -computed. The new value could be set into the variable beg_pmt. The two payments -could then be viewed with the u command. The difference could then be computed -between the two payment methods: - -

-<>n=30*12
-        360
-<>i=7.25
-        7.25
-<>pv=233350
-        233,350
-<>PMT
-        -1,591.86
-<>end_pmt=pmt
-        -1,591.86
-<>bep=1
-        1
-<>PMT
-        -1,582.30
-<>beg_pmt=pmt
-        -1,582.30
-<>u
-
-Financial Calculator
-Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-Current Financial Calculator Status:
-User Defined Variables:
-end_pmt == -1,591.86
-beg_pmt == -1,582.30
-<>beg_pmt-end_pmt
-        9.56
-<>
-
- -

The financial calculator is thus a true calculator and can be used for computations -desired by the user beyond those performed by the functions of the utility. - - -

Rounding

-

Note that the output of the calculator is rounded to the nearest cent for floating -point values. Sometimes the full accuracy of the value is desired. This can be obtained -by redefing the calculator variable ofmt to the string "%.15g". You might want to -save the current value in a user variable for resetting. For example in the above -conventional mortgage, the exact value of the periodic payment can be displayed as: - -

-<>sofmt=ofmt
-        "%.2f"
-<>ofmt="%.15g"
-        "%.15g"
-<>pmt=_PMT(n,i,pv,fv,CF,PF,disc,bep)
-        -1,591.85834951112
-<>ofmt=sofmt
-        "%.2f"
-<>
-
- -

Note that the current value of the output format string, ofmt, has been -saved in the variable, sofmt, and later restored. - - -

Examples

- - - - - - - - - - -

Simple Interest

-

Simple Interest -

Find the annual simple interest rate (%) for an $800 loan to be repayed at the - end of one year with a single payment of $896. -

- <>d
- <>CF=PF=1
-         1
- <>n=1
-         1
- <>pv=-800
-         -800
- <>fv=896
-         896
- <>I
-         12.00
-
- - -

Compound Interest

-

Compound Interest -

Find the future value of $800 after one year at a nominal rate of 12% - compounded monthly. No payments are specified, so the payment frequency is - set equal to the compounding frequency at the default values. -

- <>d
- <>n=12
-         12
- <>i=12
-         12
- <>pv=-800
-         -800
- <>FV
-          901.46
-
- - -

Periodic Payment

-

Periodic Payment -

Find the monthly end-of-period payment required to fully amortize the loan - in Example 2. A fully amortized loan has a future value of zero. -

- <>fv=0
-        0
- <>PMT
-        71.08
-
- - -

Conventional Mortgage

-

Conventional Mortgage -

Find the number of monthly payments necessary to fully amortize a loan of - $100,000 at a nominal rate of 13.25% compounded monthly, if monthly end-of-period - payments of $1125.75 are made. -

- <>d
- <>i=13.25
-         13.25
- <>pv=100000
-         100,000
- <>pmt=-1125.75
-         -1,125.75
- <>N
-         360.10
-
- - -

Final Payment

-

Final Payment -

Using the data in the above example, find the amount of the final payment if n is -changed to 360. The final payment will be equal to the regular payment plus -any balance, future value, remaining at the end of period number 360. -

- <>n=int(n)
-        360
- <>FV
-        -108.87
- <>pmt+fv
-        -1,234.62
-
- - -

Conventional Mortgage Amortization Schedule - Annual Summary

-

Conventional Mortgage Amortization Schedule - Annual Summary -

Using the data from the loan in the previous example, compute the amortization -schedule when the -Effective date of the loan is June 6, 1996 and the initial payment is -made on August 1, 1996. Ignore any change in the PV due to the delayed -initial payment caused by the partial payment period from June 6 to July 1. - -

- <>ED=6/6/1996
- Effective Date set: (2450241) Thu Jun 06 00:00:00 1996
- <>IP=8/1/96
- Initial Payment Date set: (2450297) Thu Aug 01 00:00:00 1996
- <>a
-   Effective       Date: Thu Jun 06 00:00:00 1996
-   Initial Payment Date: Thu Aug 01 00:00:00 1996
-   The amortization options are:
-   The Old Present Value (pv)     was: 100,000.00
-   The Old Periodic Payment (pmt) was: -1,125.75
-   The Old Future  Value (fv)     was: -108.87
-   1: Amortize with Original Transaction Values
-       and final payment: -1,125.75
-
-   The New Present Value (pve)  is:  100,919.30
-   The New Periodic Payment (pmt) is:  -1,136.10
-   2: Amortize with Original Periodic Payment
-       and final payment: -49,023.68
-   3: Amortize with New Periodic Payment
-       and final payment: -1,132.57
-   4: Amortize with Original Periodic Payment,
-       new number of total payments (n): 417
-       and final payment: -2,090.27
-
-   Enter choice 1, 2, 3 or 4: <>
-
- -

Press '1' to choose option 1: - -

-    Amortization Schedule:
-   Yearly, y, per Payment, p, or Advanced Payment, a, Amortization
-   Enter choice y, p or a:
-   <>
-
- -

Press 'y' for an annual summary: - -

-   Enter Filename for Amortization Schedule.
-     (null string uses Standard Output):
-
- -

Press enter to display output on screen: - -

-  Amortization Table
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  Compounding Frequency per year: 12
-  Payment     Frequency per year: 12
-  Compounding: Discrete
-  Payments: End of Period
-  Payments (359): -1,125.75
-  Final payment (# 360): -1,125.75
-  Nominal Annual Interest Rate: 13.25
-    Effective Interest Rate Per Payment Period: 0.0110417
-  Present Value: 100,000.00
-  Year      Interest   Ending Balance
-  1996     -5,518.42       -99,889.67
-  1997    -13,218.14       -99,598.81
-  1998    -13,177.17       -99,266.98
-  1999    -13,130.43       -98,888.41
-  2000    -13,077.11       -98,456.52
-  2001    -13,016.28       -97,963.80
-  2002    -12,946.88       -97,401.68
-  2003    -12,867.70       -96,760.38
-  2004    -12,777.38       -96,028.76
-  2005    -12,674.33       -95,194.09
-  2006    -12,556.76       -94,241.85
-  2007    -12,422.64       -93,155.49
-  2008    -12,269.63       -91,916.12
-  2009    -12,095.06       -90,502.18
-  2010    -11,895.91       -88,889.09
-  2011    -11,668.70       -87,048.79
-  2012    -11,409.50       -84,949.29
-  2013    -11,113.78       -82,554.07
-  2014    -10,776.41       -79,821.48
-  2015    -10,391.53       -76,704.01
-  2016     -9,952.43       -73,147.44
-  2017     -9,451.49       -69,089.93
-  2018     -8,879.99       -64,460.92
-  2019     -8,227.99       -59,179.91
-  2020     -7,484.16       -53,155.07
-  2021     -6,635.56       -46,281.63
-  2022     -5,667.43       -38,440.06
-  2023     -4,562.94       -29,494.00
-  2024     -3,302.89       -19,287.89
-  2025     -1,865.36        -7,644.25
-  2026       -236.00          -108.87
-
-  Total Interest: -305,270.00
-
- -

NOTE: The amortization table leaves the FV as it was when the amortization -function was entered. Thus, a balance of 108.87 is due at the end of the -table. To completely pay the loan, set fv to 0.0: -

-<>fv=0
-    0
-<>a
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  The amortization options are:
-  The Old Present Value (pv)     was: 100,000.00
-  The Old Periodic Payment (pmt) was: -1,125.75
-  The Old Future  Value (fv)     was: 0.00
-  1: Amortize with Original Transaction Values
-      and final payment: -1,234.62
-
-  The New Present Value (pve)  is:  100,919.30
-  The New Periodic Payment (pmt) is:  -1,136.12
-  2: Amortize with Original Periodic Payment
-      and final payment: -49,132.55
-  3: Amortize with New Periodic Payment
-      and final payment: -1,148.90
-  4: Amortize with Original Periodic Payment,
-      new number of total payments (n): 417
-      and final payment: -2,199.14
-
-  Enter choice 1, 2, 3 or 4: <>
-
- -

Press '1' for option 1: - -

-    Amortization Schedule:
-   Yearly, y, per Payment, p, or Advanced Payment, a, Amortization
-   Enter choice y, p or a:
-   <>
-
- -

Press 'y' for annual summary: - -

-   Enter Filename for Amortization Schedule.
-     (null string uses Standard Output):
-
- -

Press enter to display output on screen: - -

-  Amortization Table
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  Compounding Frequency per year: 12
-  Payment     Frequency per year: 12
-  Compounding: Discrete
-  Payments: End of Period
-  Payments (359): -1,125.75
-  Final payment (# 360): -1,234.62
-  Nominal Annual Interest Rate: 13.25
-    Effective Interest Rate Per Payment Period: 0.0110417
-  Present Value: 100,000.00
-  Year      Interest   Ending Balance
-  1996     -5,518.42       -99,889.67
-  1997    -13,218.14       -99,598.81
-  1998    -13,177.17       -99,266.98
-  1999    -13,130.43       -98,888.41
-  2000    -13,077.11       -98,456.52
-  2001    -13,016.28       -97,963.80
-  2002    -12,946.88       -97,401.68
-  2003    -12,867.70       -96,760.38
-  2004    -12,777.38       -96,028.76
-  2005    -12,674.33       -95,194.09
-  2006    -12,556.76       -94,241.85
-  2007    -12,422.64       -93,155.49
-  2008    -12,269.63       -91,916.12
-  2009    -12,095.06       -90,502.18
-  2010    -11,895.91       -88,889.09
-  2011    -11,668.70       -87,048.79
-  2012    -11,409.50       -84,949.29
-  2013    -11,113.78       -82,554.07
-  2014    -10,776.41       -79,821.48
-  2015    -10,391.53       -76,704.01
-  2016     -9,952.43       -73,147.44
-  2017     -9,451.49       -69,089.93
-  2018     -8,879.99       -64,460.92
-  2019     -8,227.99       -59,179.91
-  2020     -7,484.16       -53,155.07
-  2021     -6,635.56       -46,281.63
-  2022     -5,667.43       -38,440.06
-  2023     -4,562.94       -29,494.00
-  2024     -3,302.89       -19,287.89
-  2025     -1,865.36        -7,644.25
-  2026       -344.87             0.00
-
-  Total Interest: -305,378.87
-
- -

Note that now the final payment differs from the periodic payment and -the loan has been fully paid off. - - -

Conventional Mortgage Amortization Schedule - Periodic Payment Schedule

-

Conventional Mortgage Amortization Schedule - Periodic Payment Schedule -

Using the loan in the previous example, compute the amortization table and display the -results for each payment period. -As in example 6, ignore any increase in the PV due to the -delayed IP. - -

-<>
-  Amortization Table
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  Compounding Frequency per year: 12
-  Payment     Frequency per year: 12
-  Compounding: Discrete
-  Payments: End of Period
-  Payments (359): -1,125.75
-  Final payment (# 360): -1,234.62
-  Nominal Annual Interest Rate: 13.25
-    Effective Interest Rate Per Payment Period: 0.0110417
-  Present Value: 100,000.00
-  Pmt#       Interest      Principal        Balance
-     1      -1,104.17         -21.58     -99,978.42
-     2      -1,103.93         -21.82     -99,956.60
-     3      -1,103.69         -22.06     -99,934.54
-     4      -1,103.44         -22.31     -99,912.23
-     5      -1,103.20         -22.55     -99,889.68
-  Summary for 1996:
-    Interest  Paid: -5,518.43
-    Principal Paid: -110.32
-    Year Ending Balance: -99,889.68
-    Sum of Interest Paid: -5,518.43
-  Pmt#       Interest      Principal        Balance
-     6      -1,102.95         -22.80     -99,866.88
-     7      -1,102.70         -23.05     -99,843.83
-     8      -1,102.44         -23.31     -99,820.52
-     9      -1,102.18         -23.57     -99,796.95
-    10      -1,101.92         -23.83     -99,773.12
-    11      -1,101.66         -24.09     -99,749.03
-    12      -1,101.40         -24.35     -99,724.68
-    13      -1,101.13         -24.62     -99,700.06
-    14      -1,100.85         -24.90     -99,675.16
-    15      -1,100.58         -25.17     -99,649.99
-    16      -1,100.30         -25.45     -99,624.54
-    17      -1,100.02         -25.73     -99,598.81
-  Summary for 1997:
-    Interest  Paid: -13,218.13
-    Principal Paid: -290.87
-    Year Ending Balance: -99,598.81
-    Sum of Interest Paid: -18,736.56
-  Pmt#       Interest      Principal        Balance
-    18      -1,099.74         -26.01     -99,572.80
-    19      -1,099.45         -26.30     -99,546.50
-    .
-    .
-    .
-   346        -171.99        -953.76     -14,622.84
-   347        -161.46        -964.29     -13,658.55
-   348        -150.81        -974.94     -12,683.61
-   349        -140.05        -985.70     -11,697.91
-   350        -129.16        -996.59     -10,701.32
-   351        -118.16      -1,007.59      -9,693.73
-   352        -107.03      -1,018.72      -8,675.01
-   353         -95.79      -1,029.96      -7,645.05
-  Summary for 2025:
-    Interest  Paid: -1,865.45
-    Principal Paid: -11,643.55
-    Year Ending Balance: -7,645.05
-    Sum of Interest Paid: -305,034.80
-  Pmt#       Interest      Principal        Balance
-   354         -84.41      -1,041.34      -6,603.71
-   355         -72.92      -1,052.83      -5,550.88
-   356         -61.29      -1,064.46      -4,486.42
-   357         -49.54      -1,076.21      -3,410.21
-   358         -37.65      -1,088.10      -2,322.11
-   359         -25.64      -1,100.11      -1,222.00
-  Final Payment (360): -1,235.49
-   360         -13.49      -1,222.00           0.00
-  Summary for 2026:
-    Interest  Paid: -344.94
-    Principal Paid: -7,645.05
-
-  Total Interest: -305,379.74
-
- -

The complete amortization table can be viewed in the -Periodic Amortization Schedule for this loan. - -

You will notice several differences between this amortization schedule and the -Annual Summary Schedule. The Periodic Payment Schedule lists the interest paid for -each payment as well as the principal paid and the remaining balance to be repaid. -At the end of each year an annual summary is printed. At the end of the table the -total interest is printed as in the Annual Summary Schedule. - -

You will notice that the total interest output at the end of the Periodic Payment -Schedule differs slightly from the total interest output at the end of the Annual Summary -Schedule: - -

Total Interest for Periodic Payment Schedule: -

-  Total Interest: -305,379.74
-
- -

Total Interest for Annual Summary Schedule: - -

-  Total Interest: -305,378.87
-
- -

The difference in total interest is due to the rounding of all quantities at -each periodic payment. The Total Interest paid shown in the Periodic Payment -Schedule will be the more accurate since all quantities exchanged in a financial -transaction will be done to the nearest cent. - - -

Conventional Mortgage Schedule - Variable Advanced Payments

-

Conventional Mortgage Schedule - Variable Advanced Payments -

Again using the loan in the previous examples, compute the amortization table using -the advanced payment -option to prepay the loan. As in the previous example, ignore any increase in the PV due to the -delayed IP. - -

-
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  The amortization options are:
-  The Old Present Value (pv)     was: 100,000.00
-  The Old Periodic Payment (pmt) was: -1,125.75
-  The Old Future  Value (fv)     was: 0.00
-  1: Amortize with Original Transaction Values
-      and final payment: -1,234.62
-
-  The New Present Value (pve)  is:  100,919.30
-  The New Periodic Payment (pmt) is:  -1,136.12
-  2: Amortize with Original Periodic Payment
-      and final payment: -49,132.55
-  3: Amortize with New Periodic Payment
-      and final payment: -1,148.90
-  4: Amortize with Original Periodic Payment,
-      new number of total payments (n): 417
-      and final payment: -2,199.14
-
-  Enter choice 1, 2, 3 or 4: <>
-
- -

Press 1 for option 1: - -

-   Amortization Schedule:
-  Yearly, y, per Payment, p, or Advanced Payment, a, Amortization
-  Enter choice y, p or a:
-  <>
-
- -

Press a for the Advanced Payment Option: - -

-  Enter Filename for Amortization Schedule.
-    (null string uses Standard Output):
-
- -

Press enter to display output on screen: - -

-  Amortization Table
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  Compounding Frequency per year: 12
-  Payment     Frequency per year: 12
-  Compounding: Discrete
-  Payments: End of Period
-  Payments (359): -1,125.75
-  Final payment (# 360): -1,234.62
-  Nominal Annual Interest Rate: 13.25
-    Effective Interest Rate Per Payment Period: 0.0110417
-  Present Value: 100,000.00
-  Advanced Prepayment Amortization
-  Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
-     1    -1,104.17       -21.58       -21.82    -1,147.57   -99,956.60
-     2    -1,103.69       -22.06       -22.31    -1,148.06   -99,912.23
-     3    -1,103.20       -22.55       -22.80    -1,148.55   -99,866.88
-     4    -1,102.70       -23.05       -23.31    -1,149.06   -99,820.52
-     5    -1,102.18       -23.57       -23.83    -1,149.58   -99,773.12
-  Summary for 1996:
-    Interest  Paid: -5,515.94
-    Principal Paid: -226.88
-    Year Ending Balance: -99,773.12
-    Sum of Interest Paid: -5,515.94
-  Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
-     6    -1,101.66       -24.09       -24.35    -1,150.10   -99,724.68
-     7    -1,101.13       -24.62       -24.90    -1,150.65   -99,675.16
-     8    -1,100.58       -25.17       -25.45    -1,151.20   -99,624.54
-     9    -1,100.02       -25.73       -26.01    -1,151.76   -99,572.80
-    10    -1,099.45       -26.30       -26.59    -1,152.34   -99,519.91
-    11    -1,098.87       -26.88       -27.18    -1,152.93   -99,465.85
-    12    -1,098.27       -27.48       -27.78    -1,153.53   -99,410.59
-    13    -1,097.66       -28.09       -28.40    -1,154.15   -99,354.10
-    14    -1,097.03       -28.72       -29.03    -1,154.78   -99,296.35
-    15    -1,096.40       -29.35       -29.68    -1,155.43   -99,237.32
-    16    -1,095.75       -30.00       -30.34    -1,156.09   -99,176.98
-    17    -1,095.08       -30.67       -31.01    -1,156.76   -99,115.30
-  Summary for 1997:
-    Interest  Paid: -13,181.90
-    Principal Paid: -657.82
-    Year Ending Balance: -99,115.30
-    Sum of Interest Paid: -18,697.84
-  Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
-    18    -1,094.40       -31.35       -31.70    -1,157.45   -99,052.25
-    19    -1,093.70       -32.05       -32.40    -1,158.15   -98,987.80
-    20    -1,092.99       -32.76       -33.12    -1,158.87   -98,921.92
-    .
-    .
-    .
-   167      -298.87      -826.88      -836.01    -1,961.76   -25,404.90
-   168      -280.51      -845.24      -854.57    -1,980.32   -23,705.09
-   169      -261.74      -864.01      -873.55    -1,999.30   -21,967.53
-   170      -242.56      -883.19      -892.94    -2,018.69   -20,191.40
-   171      -222.95      -902.80      -912.77    -2,038.52   -18,375.83
-   172      -202.90      -922.85      -933.04    -2,058.79   -16,519.94
-   173      -182.41      -943.34      -953.76    -2,079.51   -14,622.84
-  Summary for 2010:
-    Interest  Paid: -3,448.07
-    Principal Paid: -20,232.96
-    Year Ending Balance: -14,622.84
-    Sum of Interest Paid: -152,300.57
-  Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
-   174      -161.46      -964.29      -974.94    -2,100.69   -12,683.61
-   175      -140.05      -985.70      -996.59    -2,122.34   -10,701.32
-   176      -118.16    -1,007.59    -1,018.72    -2,144.47    -8,675.01
-   177       -95.79    -1,029.96    -1,041.34    -2,167.09    -6,603.71
-   178       -72.92    -1,052.83    -1,064.46    -2,190.21    -4,486.42
-   179       -49.54    -1,076.21    -1,088.10    -2,213.85    -2,322.11
-   180       -25.64    -1,100.11    -1,222.00    -2,347.75         0.00
-  Summary for 2011:
-    Interest  Paid: -663.56
-    Principal Paid: -14,622.84
-
-  Total Interest: -152,964.13
-
- -

The complete amortization table can be viewed in the -Advanced Payment Amortization Schedule for this loan. - -

This schedule has added two columns over the Periodic Payment Schedule in Example 7. Namely, -Prepay and the Total Pmt columns. The Prepay column is the -amount of the loan prepayment for the period. The Total Pmt column is the sum -of the periodic payment and the Prepayment. Note that both the Prepay and the -Total Pmt quantities increase with each period. - - -

Conventional Mortgage Schedule - Constant Advanced Payments

-

Conventional Mortgage Schedule - Constant Advanced Payments -

Using the loan in the previous examples, compute the amortization table using -another payment option for repaying a loan ahead of schedule and reducing the interest -paid, constant repayments at each periodic payment. Suppose a constant $100.00 is paid -towards the principal with each periodic payment. How many payments are needed to fully payoff -the loan and what is the total interest paid? - -

As in the previous example, ignore any increase in the PV due to the -delayed IP. - -

There are two ways to compute the amortization table for this type of prepayment option. -In the first method, set the variable 'FP' to the amount of the monthly prepayment. - -

-<>FP=-100
-  -100
-<>a
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  The amortization options are:
-  The Old Present Value (pv)     was: 100,000.00
-  The Old Periodic Payment (pmt) was: -1,125.75
-  The Old Future  Value (fv)     was: 0.00
-  1: Amortize with Original Transaction Values
-      and final payment: -1,234.62
-
-  The New Present Value (pve)  is:  100,919.30
-  The New Periodic Payment (pmt) is:  -1,136.12
-  2: Amortize with Original Periodic Payment
-      and final payment: -49,132.55
-  3: Amortize with New Periodic Payment
-      and final payment: -1,148.90
-  4: Amortize with Original Periodic Payment,
-      new number of total payments (n): 417
-      and final payment: -2,199.14
-
-  Enter choice 1, 2, 3 or 4: <>
-
- -

Press 1 for option 1: - -

-   Amortization Schedule:
-  Yearly, y, per Payment, p, Advanced Payment, a, or Fixed Prepayment, f, Amortization
-  Enter choice y, p, a or f:
-  <>
-
- -

Press f for the Fixed Prepayment schedule. - -

-  Enter Filename for Amortization Schedule.
-    (null string uses Standard Output):
-
- -

Press enter to display output on screen: - -

-Amortization Table
-Effective       Date: Thu Jun  6 00:00:00 1996
-Initial Payment Date: Thu Aug  1 00:00:00 1996
-Compounding Frequency per year: 12
-Payment     Frequency per year: 12
-Compounding: Discrete
-Payments: End of Period
-Payments (359): -1,125.75
-Final payment (# 360): -1,234.62
-Nominal Annual Interest Rate: 13.25
-  Effective Interest Rate Per Payment Period: 0.0110417
-Present Value: 100,000.00
-Advanced Prepayment Amortization - fixed prepayment: -100.00
-Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
-   1    -1,104.17       -21.58      -100.00    -1,225.75   -99,878.42
-   2    -1,102.82       -22.93      -100.00    -1,225.75   -99,755.49
-   3    -1,101.47       -24.28      -100.00    -1,225.75   -99,631.21
-   4    -1,100.09       -25.66      -100.00    -1,225.75   -99,505.55
-   5    -1,098.71       -27.04      -100.00    -1,225.75   -99,378.51
-Summary for 1996:
-  Interest  Paid: -5,507.26
-  Principal Paid: -621.49
-  Year Ending Balance: -99,378.51
-  Sum of Interest Paid: -5,507.26
-Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
-   6    -1,097.30       -28.45      -100.00    -1,225.75   -99,250.06
-   7    -1,095.89       -29.86      -100.00    -1,225.75   -99,120.20
-   8    -1,094.45       -31.30      -100.00    -1,225.75   -98,988.90
-   9    -1,093.00       -32.75      -100.00    -1,225.75   -98,856.15
-  10    -1,091.54       -34.21      -100.00    -1,225.75   -98,721.94
-  11    -1,090.05       -35.70      -100.00    -1,225.75   -98,586.24
-  12    -1,088.56       -37.19      -100.00    -1,225.75   -98,449.05
-  13    -1,087.04       -38.71      -100.00    -1,225.75   -98,310.34
-  14    -1,085.51       -40.24      -100.00    -1,225.75   -98,170.10
-  15    -1,083.96       -41.79      -100.00    -1,225.75   -98,028.31
-  16    -1,082.40       -43.35      -100.00    -1,225.75   -97,884.96
-  17    -1,080.81       -44.94      -100.00    -1,225.75   -97,740.02
-Summary for 1997:
-  Interest  Paid: -13,070.51
-  Principal Paid: -1,638.49
-  Year Ending Balance: -97,740.02
-  Sum of Interest Paid: -18,577.77
-.
-.
-.
-
-Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
- 186      -298.60      -827.15      -100.00    -1,225.75   -26,115.84
- 187      -288.36      -837.39      -100.00    -1,225.75   -25,178.45
- 188      -278.01      -847.74      -100.00    -1,225.75   -24,230.71
- 189      -267.55      -858.20      -100.00    -1,225.75   -23,272.51
- 190      -256.97      -868.78      -100.00    -1,225.75   -22,303.73
- 191      -246.27      -879.48      -100.00    -1,225.75   -21,324.25
- 192      -235.46      -890.29      -100.00    -1,225.75   -20,333.96
- 193      -224.52      -901.23      -100.00    -1,225.75   -19,332.73
- 194      -213.47      -912.28      -100.00    -1,225.75   -18,320.45
- 195      -202.29      -923.46      -100.00    -1,225.75   -17,296.99
- 196      -190.99      -934.76      -100.00    -1,225.75   -16,262.23
- 197      -179.56      -946.19      -100.00    -1,225.75   -15,216.04
-Summary for 2012:
-  Interest  Paid: -2,882.05
-  Principal Paid: -11,826.95
-  Year Ending Balance: -15,216.04
-  Sum of Interest Paid: -156,688.79
-Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
- 198      -168.01      -957.74      -100.00    -1,225.75   -14,158.30
- 199      -156.33      -969.42      -100.00    -1,225.75   -13,088.88
- 200      -144.52      -981.23      -100.00    -1,225.75   -12,007.65
- 201      -132.58      -993.17      -100.00    -1,225.75   -10,914.48
- 202      -120.51    -1,005.24      -100.00    -1,225.75    -9,809.24
- 203      -108.31    -1,017.44      -100.00    -1,225.75    -8,691.80
- 204       -95.97    -1,029.78      -100.00    -1,225.75    -7,562.02
- 205       -83.50    -1,042.25      -100.00    -1,225.75    -6,419.77
- 206       -70.88    -1,054.87      -100.00    -1,225.75    -5,264.90
- 207       -58.13    -1,067.62      -100.00    -1,225.75    -4,097.28
- 208       -45.24    -1,080.51      -100.00    -1,225.75    -2,916.77
- 209       -32.21    -1,093.54      -100.00    -1,225.75    -1,723.23
-Summary for 2013:
-  Interest  Paid: -1,216.19
-  Principal Paid: -13,492.81
-  Year Ending Balance: -1,723.23
-  Sum of Interest Paid: -157,904.98
-Pmt#     Interest    Principal       Prepay    Total Pmt      Balance
- 210       -19.03    -1,106.72      -100.00    -1,225.75      -516.51
- 211        -5.70      -516.51         0.00      -522.21         0.00
-
-Total Interest: 157,929.71
-
-
- -

In the second method, the periodic payment is increased by 100. With this method, -the annual summary table can also be computed. - -

-<>s
-Financial Calculator
-Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-Current Financial Calculator Status:
-Compounding Frequency: (CF) 12
-Payment     Frequency: (PF) 12
-Compounding: Discrete (disc = TRUE)
-Payments: End of Period (bep = FALSE)
-Number of Payment Periods (n): 360              (Years: 30)
-Nominal Annual Interest Rate (i): 13.25
-  Effective Interest Rate Per Payment Period: 0.0110417
-Present Value (pv): 100,000.00
-Periodic Payment (pmt): -1,125.75
-Future Value (fv): 0.00
-Effective       Date: Thu Jun 06 00:00:00 1996(2450241)
-Initial Payment Date: Thu Aug 01 00:00:00 1996(2450297)
-<>pmt-=100
-        -1,225.75
-<>N
-        210.42
-<>
-
- -

Thus, the loan will now be fully repaid in 210 full payments and a partial payment -as illustrated in the previous table. -To get the total interest paid, display the Annual Summary Amortization Schedule: - -

-Effective       Date: Thu Jun 06 00:00:00 1996
-Initial Payment Date: Thu Aug 01 00:00:00 1996
-The amortization options are:
-The Old Present Value (pv)     was: 100,000.00
-The Old Periodic Payment (pmt) was: -1,225.75
-The Old Future  Value (fv)     was: 0.00
-1: Amortize with Original Transaction Values
-    and final payment: -1,742.55
-
-The New Present Value (pve)  is:  100,919.30
-The New Periodic Payment (pmt) is:  -1,237.02
-2: Amortize with Original Periodic Payment
-    and final payment: -10,967.39
-3: Amortize with New Periodic Payment
-    and final payment: -1,757.20
-4: Amortize with Original Periodic Payment,
-    new number of total payments (n): 218
-    and final payment: -1,668.45
-
-Enter choice 1, 2, 3 or 4: <>
-
- -

Press '1' for option 1: - -

- Amortization Schedule:
-Yearly, y, per Payment, p, or Advanced Payment, a, Amortization
-Enter choice y, p or a:
-<>
-
- -

Press 'y' for an annual Summary - -

-Enter Filename for Amortization Schedule.
-  (null string uses Standard Output):
-
- -

Press enter to display the summary on the screen: - -

-  Amortization Table
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  Compounding Frequency per year: 12
-  Payment     Frequency per year: 12
-  Compounding: Discrete
-  Payments: End of Period
-  Payments (209): -1,225.75
-  Final payment (# 210): -1,742.55
-  Nominal Annual Interest Rate: 13.25
-    Effective Interest Rate Per Payment Period: 0.0110417
-  Present Value: 100,000.00
-  Year      Interest   Ending Balance
-  1996     -5,507.26       -99,378.51
-  1997    -13,070.52       -97,740.03
-  1998    -12,839.74       -95,870.77
-  1999    -12,576.45       -93,738.22
-  2000    -12,276.08       -91,305.30
-  2001    -11,933.40       -88,529.70
-  2002    -11,542.46       -85,363.16
-  2003    -11,096.45       -81,750.61
-  2004    -10,587.62       -77,629.23
-  2005    -10,007.12       -72,927.35
-  2006     -9,344.86       -67,563.21
-  2007     -8,589.32       -61,443.53
-  2008     -7,727.36       -54,461.89
-  2009     -6,744.00       -46,496.89
-  2010     -5,622.13       -37,410.02
-  2011     -4,342.24       -27,043.26
-  2012     -2,882.08       -15,216.34
-  2013     -1,216.25        -1,723.59
-  2014        -18.96             0.00
-
-  Total Interest: -157,924.30
-
- -

From the last line the Total interest has been decreased from $305,379.74 to -$157,924.30. - -

We can also ask how much of a constant repayment would be necessary to fully -repay the loan in 15 years and what would be the total interest paid? - -

-  <>n=12*15
-          180
-  <>opmt=pmt
-          -1,125.75
-  <>PMT
-          -1,281.74
-  <>pmt-opmt
-          -155.99
-
- -

Thus, a constant advanced repayment per periodic payment of $155.99 would fully -amortize the loan in 15 years. - -

-  <>a
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  The amortization options are:
-  The Old Present Value (pv)     was: 100,000.00
-  The Old Periodic Payment (pmt) was: -1,281.74
-  The Old Future  Value (fv)     was: 0.00
-  1: Amortize with Original Transaction Values
-      and final payment: -1,279.73
-
-  The New Present Value (pve)  is:  100,919.30
-  The New Periodic Payment (pmt) is:  -1,293.52
-  2: Amortize with Original Periodic Payment
-      and final payment: -7,915.43
-  3: Amortize with New Periodic Payment
-      and final payment: -1,293.20
-  4: Amortize with Original Periodic Payment,
-      new number of total payments (n): 185
-      and final payment: -1,738.05
-
-  Enter choice 1, 2, 3 or 4: <>
-
- -

Press '1' for option 1: - -

-   Amortization Schedule:
-  Yearly, y, per Payment, p, or Advanced Payment, a, Amortization
-  Enter choice y, p or a:
-  <>
-
- -

Press 'y' for an annual Summary - -

-  Amortization Table
-  Effective       Date: Thu Jun 06 00:00:00 1996
-  Initial Payment Date: Thu Aug 01 00:00:00 1996
-  Compounding Frequency per year: 12
-  Payment     Frequency per year: 12
-  Compounding: Discrete
-  Payments: End of Period
-  Payments (179): -1,281.74
-  Final payment (# 180): -1,279.73
-  Nominal Annual Interest Rate: 13.25
-    Effective Interest Rate Per Payment Period: 0.0110417
-  Present Value: 100,000.00
-  Year      Interest   Ending Balance
-  1996     -5,501.01       -99,092.31
-  1997    -12,987.86       -96,699.29
-  1998    -12,650.80       -93,969.21
-  1999    -12,266.27       -90,854.60
-  2000    -11,827.58       -87,301.30
-  2001    -11,327.09       -83,247.51
-  2002    -10,756.12       -78,622.75
-  2003    -10,104.72       -73,346.59
-  2004     -9,361.57       -67,327.28
-  2005     -8,513.75       -60,460.15
-  2006     -7,546.51       -52,625.78
-  2007     -6,443.04       -43,687.94
-  2008     -5,184.14       -33,491.20
-  2009     -3,747.93       -21,858.25
-  2010     -2,109.42        -8,586.79
-  2011       -383.38             0.00
-
-  Total Interest: -130,711.19
-
- -

The toral interest is reduced to $130,711.19. This compares to: - -

    -
  1. $130,711.19 - Fixed prepayment $155.99/period, 15 year term -
  2. $152,964.13 - Variable Advanced Repayment, 15 year term -
  3. $305,379.74 - no prepayment, 30 year term -
- - -

Balloon Payment

-

Balloon Payment -

On long term loans, small changes in the periodic payments can generate -large changes in the future value. If the monthly payment in the previous example is -rounded down to $1125, how much additional (balloon) payment will be due -with the final regular payment. -

-  <>s
-  Financial Calculator
-  Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-  Current Financial Calculator Status:
-  Compounding Frequency: (CF) 12
-  Payment     Frequency: (PF) 12
-  Compounding: Discrete (disc = TRUE)
-  Payments: End of Period (bep = FALSE)
-  Number of Payment Periods (n): 180              (Years: 15)
-  Nominal Annual Interest Rate (i): 13.25
-    Effective Interest Rate Per Payment Period: 0.0110417
-  Present Value (pv): 100,000.00
-  Periodic Payment (pmt): -1,281.74
-  Future Value (fv): 0.00
-  Effective       Date: Thu Jun 06 00:00:00 1996(2450241)
-  Initial Payment Date: Thu Aug 01 00:00:00 1996(2450297)
-  <>n=360
-          360
-  <>pmt=-1125
-          -1,125
-  <>FV
-          -3,579.99
-  <>
-
- - -

Canadian Mortgage

-

Canadian Mortgage -

A "Canadian Mortgage" is defined with semi-annual compunding, CF == 2, -and monthly payments, PF == 12. - -

Find the monthly end-of-period payment necessary to fully amortize a 25 year -$85,000 loan at 11% compounded semi-annually. -

- <>d
- <>CF=2
-         2
- <>n=300
-         300
- <>i=11
-         11
- <>pv=85000
-         85,000
- <>PMT
-         -818.15
-
- - -

-

European Mortgage -

The "effective annual rate (EAR)" is used in some countries (especially - in Europe) in lieu of the nominal rate commonly used in the United States - and Canada. For a 30 year $90,000 mortgage at 14% (EAR), compute the monthly - end-of-period payments. When using an EAR, the compounding frequency is - set to 1. -

- <>d
- <>CF=1
-         1
- <>n=30*12
-         360
- <>i=14
-         14
- <>pv=90000
-         90,000
- <>PMT
-         -1,007.88
-
- - -

Bi-weekly Savings

-

Bi-weekly Savings -

Compute the future value, fv, of bi-weekly savings of $100 for 3 years at a - nominal annual rate of 5.5% compounded daily. (Set payment to - beginning-of-period, bep = TRUE) -

- <>d
- <>bep=TRUE
-         1
- <>CF=365
-         365
- <>PF=26
-         26
- <>n=3*26
-         78
- <>i=5.5
-         5.50
- <>pmt=-100
-         -100
- <>FV
-         8,489.32
-
- - -

Present Value - Annuity Due

-

Present Value - Annuity Due -

What is the present value of $500 to be received at the beginning of each - quarter over a 10 year period if money is being discounted at 10% nominal - annual rate compounded monthly? -

- <>d
- <>bep=TRUE
-         1
- <>PF=4
-         4
- <>n=4*10
-         40
- <>i=10
-         10
- <>pmt=500
-         500
- <>PV
-         -12,822.64
-
- - -

Effective Rate - 365/360 Basis

-

Effective Rate - 365/360 Basis -

Compute the effective annual rate (%APR) for a nominal annual rate of 12% - compounded on a 365/360 basis used by some Savings & Loan Associations. -

- <>d
- <>n=365
-         365
- <>CF=365
-         365
- <>PF=360
-         360
- <>i=12
-         12
- <>pv=-100
-         -100
- <>FV
-         112.94
- <>fv+pv
-         12.94
-
- - -

Certificate of Deposit, Annual Percentage Yield

-

Certificate of Deposit, Annual Percentage Yield -

Most, if not all banks have started stating return rates on Certificates of Deposit, CDs, as -an Annual Percentage Yoild, APY, and the nominal annual interest. For example, a bank will advertise -a CD with a 18 month term, an APY of 5.20% and a nominal rate of 5.00. What values of CF and PF will -are being used? - -

- <>d
- <>n=365
-         365
- <>CF=PF=365
-         365
- <>i=5
-         5
- <>pv=-100
-         -100
- <>FV
-         105.13
- <>CF=PF=360
-         360
- <>fv+pv
-         -5.20
-
- -

Mortgage with "Points"

-

Mortgage with "Points" -

What is the true APR of a 30 year, $75,000 loan at a nominal rate of 13.25% - compounded monthly, with monthly end-of-period payments, if 3 "points" - are charged? The pv must be reduced by the dollar value of the points - and/or any lenders fees to establish an effective pv. Because payments remain - the same, the true APR will be higher than the nominal rate. Note, first - compute the payments on the pv of the loan amount. -

-  <>n=30*12
-          360
-  <>i=13.25
-          13.25
-  <>pv=75000
-          75,000
-  <>PMT
-          -844.33
-  <>pv-=pv*0.03
-          72,750.00
-  <>I
-          13.69
-  <>
-
- - -

Equivalent Payments

-

Equivalent Payments -

Find the equivalent monthly payment required to amortize a 20 year $40,000 -loan at 10.5% nominal annual rate compounded monthly, with 10 annual -payments of $5029.71 remaining. Compute the pv of the remaining annual -payments, then change n, the number of periods, and the payment frequency, -PF, to a monthly basis and compute the equivalent monthly pmt. -

- <>d
- <>PF=1
-         1
- <>n=10
-         10
- <>i=10.5
-         10.50
- <>pmt=-5029.71
-         -5,029.71
- <>PV
-         29,595.88
- <>PF=12
-         12
- <>n=120
-         120
- <>PMT
-         -399.35
-
- - -

Perpetuity - Continuous Compounding

-

Perpetuity - Continuous Compounding -

If you can purchase a single payment annuity with an initial investment of - $60,000 that will be invested at 15% nominal annual rate compounded - continuously, what is the maximum monthly return you can receive without - reducing the $60,000 principal? If the principal is not disturbed, the - payments can go on indefinitely (a perpetuity). Note that the term,n, of - a perpetuity is immaterial. It can be any non-zero value. -

- <>d
- <>disc=FALSE
-         0
- <>n=12
-         12
- <>CF=1
-         1
- <>i=15
-         15
- <>fv=60000
-         60,000
- <>pv=-60000
-         -60,000
- <>PMT
-         754.71
-
- - -

Investment Return

-

Investment Return -

A development company is purchasing an investment property with an annual net cash -flow of $25,000.00. The expected holding period for the property is 10 years with an estimated -selling price of $850,000.00 at that time. If the company is to realize a 15% yield on the -investment, what is the maximum price they can pay for the property today? - -

-  Financial Calculator
-  Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-  <>CF=PF=1
-          1
-  <>n=10
-          10
-  <>i=15
-          15
-  <>pmt=25000
-          25,000
-  <>fv=850000
-          850,000
-  <>PV
-          -335,576.22
-
- -

So the maximum purchase price today would be $335,576.22 to achieve the desired yield. - - -

Retirement Investment

-

Retirement Investment -

You wish to retire in 20 years and wish to deposit a lump sum amount in an account -today which will grow to $100,000.00, earning 6.5% interest compounded semi-annually. -How much do you need to deposit? - -

-  Financial Calculator
-  Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-  <>CF=PF=2
-          2
-  <>n=2*20
-          40
-  <>i=6.5
-          6.50
-  <>fv=100000
-          100,000
-  <>PV
-          -27,822.59
-
- -

If you were to make semi-annual deposits of $600.00, how much would you need to deposit today? - -

-  <>pmt=-600
-          -600
-  <>PV
-          -14,497.53
-
- -

If you were to make monthly deposits of $100.00? - -

-  <>PF=12
-          12
-  <>n=20*12
-          240
-  <>pmt=-100
-          -100
-  <>PV
-          -14,318.21
-
- - -

Property Values

-

Property Values -

Property values in an area you are considering moving to are declining at the rate -of 2.35% annually. What will property presently appraised at $155,500.00 be worth in 10 years -if the trend continues? - -

-  Financial Calculator
-  Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-  <>CF=PF=1
-          1
-  <>n=10
-          10
-  <>i=-2.35
-          -2.35
-  <>pv=155500
-          155,500
-  <>FV
-          -122,589.39
-
- - -

College Expenses

-

College Expenses -

You and your spouse are planning for your child's college expenses. Your child -will be entering college in 15 years. You expect that college expenses at that time -will amount to $25,000.00 per year or about $2,100.00/month. If the child withdrew -the expenses from a bank account monthly paying 6% compounded on a daily basis (using -360 days/year), how much must you deposit in the account at the start of the four -years? - -

-  Financial Calculator
-  Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-  <>CF=360
-          360
-  <>PF=12
-          12
-  <>n=12*4
-          48
-  <>i=6
-          6
-  <>pmt=2100
-          2,100
-  <>PV
-          -89,393.32
-
- -

Your next problem is how to accumulate the money by the time the child starts college. -You have a $50,000.00 paid-up insurance policy for your child that has a cash value -of $6,500.00. It is accumulating annual dividends of $1,200 earning 6.75% compounded monthly. -What will be the cash value of the policy in 15 years? - -

-  <>college_fund=-pv
-          89,393.32
-  <>d
-  <>PF=1
-          1
-  <>n=20
-          20
-  <>i=6.75
-          6.75
-  <>pmt=1200
-          1,200
-  <>FV
-          -48,995.19
-  <>insurance=-fv+6500
-          55,495.19
-  <>college_fund-insurance
-          33,898.13
-
- -

The paid-up insurance cash value and dividends will provide $55,495.19 of the amount -necessary, leaving $33,898.13 to accumulate in savings. Making monthly payments into -a savings account paying 4.5% compounded daily, what level of monthly payments would be -needed? - -

-  Financial Calculator
-  Copyright (C) 1990 - 1997 Terry D. Boldt, All Rights Reserved.
-  <>d
-  <>CF=360
-          360
-  <>n=PF*15
-          180
-  <>i=4.5
-          4.50
-  <>fv=college_fund - insurance
-          33,898.13
-  <>PMT
-          -132.11
-
- - -

References

-
-PPC ROM User's Manual -
pages 148 - 164 -
-
-TOP - \ No newline at end of file