diff --git a/jspdf.js b/jspdf.js
index 1b38d9c05..7d2980585 100644
--- a/jspdf.js
+++ b/jspdf.js
@@ -788,16 +788,17 @@ var jsPDF = (function(global) {
 			// @TODO: Add different output options
 		});
 
-		if (unit === 'pt') {
-			k = 1;
-		} else if (unit === 'mm') {
-			k = 72 / 25.4;
-		} else if (unit === 'cm') {
-			k = 72 / 2.54;
-		} else if (unit === 'in') {
-			k = 72;
-		} else {
-			throw('Invalid unit: ' + unit);
+		switch (unit) {
+			case 'pt':  k = 1;          break;
+			case 'mm':  k = 72 / 25.4;  break;
+			case 'cm':  k = 72 / 2.54;  break;
+			case 'in':  k = 72;         break;
+			case 'px':  k = 96 / 72;    break;
+			case 'pc':  k = 12;         break;
+			case 'em':  k = 12;         break;
+			case 'ex':  k = 6;          break;
+			default:
+				throw ('Invalid unit: ' + unit);
 		}
 
 		// Dimensions are stored as user units and converted to points on output