I have made several of these and each time they come out different sizes. So I just add more material where needed. You do want it longer than wider so it will cover a person laying on a bed or snuggled up on a couch. I have made my own strips and when you get a pile sewn together about 2-3' high end to end (from the floor) you have enough for a large bed. I think we measured the last one at 80' before I started to fold and sew together.