diff --git a/core/block_svg.js b/core/block_svg.js
index b351800c8..4a1f79be1 100644
--- a/core/block_svg.js
+++ b/core/block_svg.js
@@ -348,6 +348,35 @@ Blockly.BlockSvg.prototype.getHeightWidth = function() {
   return {height: height, width: width};
 };
 
+/**
+ * Returns the coordinates of a bounding box describing the dimensions of this block
+ * and any blocks stacked below it.
+ * @return {!{topLeft: goog.math.Coordinate, bottomRight: goog.math.Coordinate}}
+ *         Object with top left and bottom right coordinates of the bounding box.
+ */
+Blockly.BlockSvg.prototype.getBoundingRectangle = function() {
+  var blockXY = this.getRelativeToSurfaceXY(this);
+  var tab = this.outputConnection ? Blockly.BlockSvg.TAB_WIDTH : 0;
+  var blockBounds = this.getHeightWidth();
+  var topLeft;
+  var bottomRight;
+  if (this.RTL) {
+    // Width has the tab built into it already so subtract it here.
+    topLeft = new goog.math.Coordinate(blockXY.x - (blockBounds.width - tab), blockXY.y);
+    // Add the width of the tab/puzzle piece knob to the x coordinate
+    // since X is the corner of the rectangle, not the whole puzzle piece.
+    bottomRight = new goog.math.Coordinate(blockXY.x + tab, blockXY.y + blockBounds.height);
+  } else {
+    // Subtract the width of the tab/puzzle piece knob to the x coordinate
+    // since X is the corner of the rectangle, not the whole puzzle piece.
+    topLeft = new goog.math.Coordinate(blockXY.x - tab, blockXY.y);
+    // Width has the tab built into it already so subtract it here.
+    bottomRight = new goog.math.Coordinate(blockXY.x + blockBounds.width - tab,
+ 					   blockXY.y + blockBounds.height);
+  }
+  return { topLeft : topLeft, bottomRight : bottomRight };
+};
+
 /**
  * Set whether the block is collapsed or not.
  * @param {boolean} collapsed True if collapsed.
diff --git a/core/blockly.js b/core/blockly.js
index d98250346..8c0cf9fb1 100644
--- a/core/blockly.js
+++ b/core/blockly.js
@@ -521,12 +521,8 @@ Blockly.getMainWorkspaceMetrics_ = function() {
   var MARGIN = Blockly.Flyout.prototype.CORNER_RADIUS - 1;
   var viewWidth = svgSize.width - MARGIN;
   var viewHeight = svgSize.height - MARGIN;
-  try {
-    var blockBox = this.getCanvas().getBBox();
-  } catch (e) {
-    // Firefox has trouble with hidden elements (Bug 528969).
-    return null;
-  }
+  var blockBox = this.getBlocksBoundingBox();
+
   // Fix scale.
   var contentWidth = blockBox.width * this.scale;
   var contentHeight = blockBox.height * this.scale;
diff --git a/core/workspace_svg.js b/core/workspace_svg.js
index 273c04d3a..52eabd6a0 100644
--- a/core/workspace_svg.js
+++ b/core/workspace_svg.js
@@ -660,6 +660,46 @@ Blockly.WorkspaceSvg.prototype.onMouseWheel_ = function(e) {
   e.preventDefault();
 };
 
+/**
+ * Calculate the bounding box for the blocks on the workspace.
+ *
+ * @return {Object} Contains the position and size of the bounding box
+ *   containing the blocks on the workspace.
+ */
+Blockly.WorkspaceSvg.prototype.getBlocksBoundingBox = function() {
+  var topBlocks = this.getTopBlocks();
+  // There are no blocks, return empty rectangle.
+  if (topBlocks.length <= 0) {
+    return {x: 0, y: 0, width: 0, height: 0};
+  }
+
+  // Initialize boundary using the first block.
+  var boundary = topBlocks[0].getBoundingRectangle();
+
+  // Start at 1 since the 0th block was used for initialization
+  for (var i = 1; i < topBlocks.length; i++) {
+    var blockBoundary = topBlocks[i].getBoundingRectangle();
+    if (blockBoundary.topLeft.x < boundary.topLeft.x) {
+      boundary.topLeft.x = blockBoundary.topLeft.x;
+    }
+    if (blockBoundary.bottomRight.x > boundary.bottomRight.x) {
+      boundary.bottomRight.x = blockBoundary.bottomRight.x
+    }
+    if (blockBoundary.topLeft.y < boundary.topLeft.y) {
+      boundary.topLeft.y = blockBoundary.topLeft.y;
+    }
+    if (blockBoundary.bottomRight.y > boundary.bottomRight.y) {
+      boundary.bottomRight.y = blockBoundary.bottomRight.y;
+    }
+  }
+  return {
+    x: boundary.topLeft.x,
+    y: boundary.topLeft.y,
+    width: boundary.bottomRight.x - boundary.topLeft.x,
+    height: boundary.bottomRight.y - boundary.topLeft.y
+  };
+};
+
 /**
  * Clean up the workspace by ordering all the blocks in a column.
  * @private