i ususally have an accurate 1/4" seam. try checking that first. I sq up when it's done. if you are accurate with the 1/4" seam, it should be o.k. but ck that first. keep in mind, if you're off even 1/16" of an inch, you can see how quickly it will add up. keep with it, it's a fun block, and can be used in many ways. show us how you do.