Full Yard - 36 inches long by 44 inches wide. (91cm x 111.5cm)
Traditional Quarter - 9 inches long by 44 inches wide (22.5cm x 111.5cm)
Fat Quarter - Cut crosswise from a 1⁄2-yard piece of fabric- a rectangle cut in half to yield an 18×22" "fat" 1⁄4-yard piece (45cm x 56cm)
Half Yard - 18 inches long by 44 inches wide. (45.5cm x 111.5cm)
A guide to the relative sizes of the various fabric cuts.