diff --git a/docs/sources/reference/templating.md b/docs/sources/reference/templating.md
index efe9db61e3d..08a142d3636 100644
--- a/docs/sources/reference/templating.md
+++ b/docs/sources/reference/templating.md
@@ -273,6 +273,9 @@ The `$__timeFilter` is used in the MySQL data source.
 
 This variable is only available in the Singlestat panel and can be used in the prefix or suffix fields on the Options tab. The variable will be replaced with the series name or alias.
 
+### The $__range Variable
+Currently only supported for Prometheus data sources. This variable represents the range for the current dashboard. It is calculated by `to - from`. It has a millisecond representation called `$__range_ms`.
+
 ## Repeating Panels
 
 Template variables can be very useful to dynamically change your queries across a whole dashboard. If you want