Increase your canvas size relatively (Photoshop CS/CS2/CS3/CS4)

The next time you have to increase the size of your canvas, check out Photoshop’s Relative option. Just choose Image > Canvas Size. Then, in the resulting Canvas Size dialog box, select the Relative check box. Now, just enter the how much space you want added to the Width and Height text boxes. It’s much easier than trying to add 1.57 inches to 22.35 inches (not that you should create documents with such random sizes, but you never know).