diff --git a/src/ol/extent.js b/src/ol/extent.js
index 08422a84d8..ea3e5cb8ce 100644
--- a/src/ol/extent.js
+++ b/src/ol/extent.js
@@ -316,6 +316,15 @@ ol.extent.extendXY = function(extent, x, y) {
 };
 
 
+/**
+ * @param {ol.Extent} extent Extent.
+ * @return {number} Area.
+ */
+ol.extent.getArea = function(extent) {
+  return ol.extent.getWidth(extent) * ol.extent.getHeight(extent);
+};
+
+
 /**
  * @param {ol.Extent} extent Extent.
  * @return {ol.Coordinate} Bottom left coordinate.