diff --git a/js/id/geo/extent.js b/js/id/geo/extent.js
index a32b5783c..912bcf08a 100644
--- a/js/id/geo/extent.js
+++ b/js/id/geo/extent.js
@@ -55,6 +55,14 @@ _.extend(iD.geo.Extent.prototype, {
         ];
     },
 
+    contains: function(obj) {
+        if (!(obj instanceof iD.geo.Extent)) obj = new iD.geo.Extent(obj);
+        return obj[0][0] >= this[0][0] &&
+               obj[0][1] >= this[0][1] &&
+               obj[1][0] <= this[1][0] &&
+               obj[1][1] <= this[1][1];
+    },
+
     intersects: function(obj) {
         if (!(obj instanceof iD.geo.Extent)) obj = new iD.geo.Extent(obj);
         return obj[0][0] <= this[1][0] &&
diff --git a/test/spec/geo/extent.js b/test/spec/geo/extent.js
index fb880548e..cd2e84cb0 100644
--- a/test/spec/geo/extent.js
+++ b/test/spec/geo/extent.js
@@ -109,6 +109,35 @@ describe("iD.geo.Extent", function () {
         });
     });
 
+    describe('#contains', function () {
+        it("returns true for a point inside self", function () {
+            expect(iD.geo.Extent([0, 0], [5, 5]).contains([2, 2])).to.be.true;
+        });
+
+        it("returns true for a point on the boundary of self", function () {
+            expect(iD.geo.Extent([0, 0], [5, 5]).contains([0, 0])).to.be.true;
+        });
+
+        it("returns false for a point outside self", function () {
+            expect(iD.geo.Extent([0, 0], [5, 5]).contains([6, 6])).to.be.false;
+        });
+
+        it("returns true for an extent contained by self", function () {
+            expect(iD.geo.Extent([0, 0], [5, 5]).contains([[1, 1], [2, 2]])).to.be.true;
+            expect(iD.geo.Extent([1, 1], [2, 2]).contains([[0, 0], [5, 5]])).to.be.false;
+        });
+
+        it("returns false for an extent partially contained by self", function () {
+            expect(iD.geo.Extent([0, 0], [5, 5]).contains([[1, 1], [6, 6]])).to.be.false;
+            expect(iD.geo.Extent([1, 1], [6, 6]).contains([[0, 0], [5, 5]])).to.be.false;
+        });
+
+        it("returns false for an extent not intersected by self", function () {
+            expect(iD.geo.Extent([0, 0], [5, 5]).contains([[6, 6], [7, 7]])).to.be.false;
+            expect(iD.geo.Extent([[6, 6], [7, 7]]).contains([[0, 0], [5, 5]])).to.be.false;
+        });
+    });
+
     describe('#intersects', function () {
         it("returns true for a point inside self", function () {
             expect(iD.geo.Extent([0, 0], [5, 5]).intersects([2, 2])).to.be.true;
@@ -127,7 +156,7 @@ describe("iD.geo.Extent", function () {
             expect(iD.geo.Extent([1, 1], [2, 2]).intersects([[0, 0], [5, 5]])).to.be.true;
         });
 
-        it("returns true for an extent intersected by self", function () {
+        it("returns true for an extent partially contained by self", function () {
             expect(iD.geo.Extent([0, 0], [5, 5]).intersects([[1, 1], [6, 6]])).to.be.true;
             expect(iD.geo.Extent([1, 1], [6, 6]).intersects([[0, 0], [5, 5]])).to.be.true;
         });