Some stores that sell photo frame replacement glass include Michael's, Lowe's and The Home Depot. The glasses come in various sizes and may, in some cases, need to be cut down to fit the exact frame size that needs replaced.
Michael's offers several options for picture frame replacement glass. It carries 11-inch by 14-inch glass along with 18-inch by 24-inch glass. The glass comes with back replacements as well. In addition to the glass options, Michael's also has polystyrene sheets with backers that allow people to make their own frames or offers an alternative to a glass replacement.
Lowe's Home Improvement stores offer 20-inch by 16-inch glass replacements that are 3/32 inches thick. While the glass does come in this pre-cut size, the store will cut the glass to the customer's specifications inside the store. This glass can also be used as a replacement in cabinets and windows.
The Home Depot offers a 30-inch by 36-inch glass replacement piece. This glass resists yellowing and fading. The Home Depot does not offer glass cutting in the store as of 2015, but they do carry a glass scoring kit that can be bought and used to cut the glass to the sized needed for the picture frame. Other stores that sell photo frame replacement glass include Frame Destination and Ace Hardware.