there are three rulers to use when making the twister pattern. The 8 1/2in ruler you cut 10" squares, The 3 1/2 in ruler you cut 5 in. squares. The 1 1/2 in. ruler you cut 3 in squares which tends to be minature in size when done. How do I know? because I purchased all three rulers. I have made several tablerunners and placemats using the 3 1/2 in ruler and the smallest one you can make mug rugs with. Haven't made anything with the big one yet.