Fat quarters are 18 x 21 or 22 inches or 1/4 of a yard of fabric. One yard of fabric is cut down the middle (20 x 36) then recut to 20 x 18. Jelly rolls are 2 1/2 strips of coordinating fabric that are bundled together. Fabric companies are now selling bundled fabrics such as charm square packages, layer cakes and more. These are all pre-cut fabrics.