diff --git a/public/app/plugins/panel/heatmap/rendering.ts b/public/app/plugins/panel/heatmap/rendering.ts
index cbfb2a52b6b..1d8cf1e4d9f 100644
--- a/public/app/plugins/panel/heatmap/rendering.ts
+++ b/public/app/plugins/panel/heatmap/rendering.ts
@@ -334,8 +334,10 @@ export default function link(scope, elem, attrs, ctrl) {
 
   function addHeatmapCanvas() {
     let heatmap_elem = $heatmap[0];
-    width = heatmap_elem.clientWidth - padding.right;
-    height = heatmap_elem.clientHeight - padding.bottom;
+
+    width = Math.floor($heatmap.width()) - padding.right;
+    height = Math.floor($heatmap.height()) - padding.bottom;
+
     cardPadding = panel.cards.cardPadding !== null ? panel.cards.cardPadding : CARD_PADDING;
     cardRound = panel.cards.cardRound !== null ? panel.cards.cardRound : CARD_ROUND;
 
diff --git a/public/app/plugins/panel/heatmap/specs/renderer_specs.ts b/public/app/plugins/panel/heatmap/specs/renderer_specs.ts
new file mode 100644
index 00000000000..2e9a6a82b4f
--- /dev/null
+++ b/public/app/plugins/panel/heatmap/specs/renderer_specs.ts
@@ -0,0 +1,165 @@
+///<reference path="../../../../headers/common.d.ts" />
+
+import { describe, beforeEach, it, sinon, expect, angularMocks } from '../../../../../test/lib/common';
+
+import '../module';
+import angular from 'angular';
+import $ from 'jquery';
+import _ from 'lodash';
+import helpers from 'test/specs/helpers';
+import TimeSeries from 'app/core/time_series2';
+import moment from 'moment';
+import { Emitter } from 'app/core/core';
+import rendering from '../rendering';
+import { convertToHeatMap } from '../heatmap_data_converter';
+// import d3 from 'd3';
+
+describe('grafanaHeatmap', function () {
+
+  beforeEach(angularMocks.module('grafana.core'));
+
+  function heatmapScenario(desc, func, elementWidth = 500) {
+    describe(desc, function () {
+      var ctx: any = {};
+
+      ctx.setup = function (setupFunc) {
+
+        beforeEach(angularMocks.module(function ($provide) {
+          $provide.value("timeSrv", new helpers.TimeSrvStub());
+        }));
+
+        beforeEach(angularMocks.inject(function ($rootScope, $compile) {
+          var ctrl: any = {
+            events: new Emitter(),
+            height: 200,
+            panel: {
+              heatmap: {
+              },
+              cards: {
+                cardPadding: null,
+                cardRound: null
+              },
+              color: {
+                mode: 'color',
+                cardColor: '#b4ff00',
+                colorScale: 'linear',
+                exponent: 0.5,
+                colorScheme: 'interpolateSpectral',
+                fillBackground: false
+              },
+              xBucketSize: null,
+              xBucketNumber: null,
+              yBucketSize: null,
+              yBucketNumber: null,
+              xAxis: {
+                show: true
+              },
+              yAxis: {
+                show: true,
+                format: 'short',
+                decimals: null,
+                logBase: 1,
+                splitFactor: null,
+                min: null,
+                max: null,
+                removeZeroValues: false
+              },
+              tooltip: {
+                show: true,
+                seriesStat: false,
+                showHistogram: false
+              },
+              highlightCards: true
+            },
+            renderingCompleted: sinon.spy(),
+            hiddenSeries: {},
+            dashboard: {
+              getTimezone: sinon.stub().returns('browser')
+            },
+            range: {
+              from: moment(1422774000000),
+              to:   moment(1422774100000),
+            },
+          };
+
+          var scope = $rootScope.$new();
+          scope.ctrl = ctrl;
+
+          let series = [];
+          series.push(new TimeSeries({
+            datapoints: [[1422774000000, 1], [1422774060000, 2]],
+            alias: 'series1'
+          }));
+          series.push(new TimeSeries({
+            datapoints: [[1422774000000, 2], [1422774060000, 3]],
+            alias: 'series2'
+          }));
+
+          setupFunc(ctrl, ctx.data);
+
+          let xBucketSize = ctrl.panel.xBucketSize;
+          let yBucketSize = ctrl.panel.yBucketSize;
+          let logBase = ctrl.panel.yAxis.logBase;
+          let bucketsData = convertToHeatMap(series, yBucketSize, xBucketSize, logBase);
+          // console.log("bucketsData", bucketsData);
+
+          ctx.data = {
+            buckets: bucketsData,
+            heatmapStats: {
+              min: 1,
+              max: 3,
+              minLog: 1
+            },
+            xBucketSize: xBucketSize,
+            yBucketSize: yBucketSize
+          };
+
+          let elemHtml = `
+          <div class="heatmap-wrapper">
+            <div class="heatmap-canvas-wrapper">
+              <div class="heatmap-panel" style='width:${elementWidth}px'></div>
+            </div>
+          </div>`;
+
+          var element = angular.element(elemHtml);
+          $compile(element)(scope);
+          scope.$digest();
+
+          ctrl.data = ctx.data;
+          ctx.element = element;
+          let render = rendering(scope, $(element), [], ctrl);
+          ctrl.events.emit('render');
+        }));
+      };
+
+      func(ctx);
+    });
+  }
+
+  heatmapScenario('default options', function (ctx) {
+    ctx.setup(function (ctrl) {
+      ctrl.panel.logBase = 1;
+      ctrl.panel.xBucketSize = 1000;
+      ctrl.panel.yBucketSize = 1;
+    });
+
+    it('should draw correct Y axis', function () {
+      var yTicks = getTicks(ctx.element, ".axis-y");
+      expect(yTicks).to.eql(['1', '2', '3']);
+    });
+
+    it('should draw correct X axis', function () {
+      var xTicks = getTicks(ctx.element, ".axis-x");
+      expect(xTicks).to.eql(['10:00:00', '10:00:15', '10:00:30', '10:00:45', '10:01:00', '10:01:15', '10:01:30']);
+    });
+  });
+
+});
+
+
+function getTicks(element, axisSelector) {
+  return element.find(axisSelector).find("text")
+    .map(function () {
+      return this.textContent;
+    }).get();
+}