I wish I could tell you how many your will need, but I made mine out of my scrap bin, but have yet to quilt it. Yours will also depend on the amount of drop (amount over the edge) you want on your quilt, and how scrappy you want it to be. Will you want one that goes down to the bed frame or wider that goes almost to the floor? At any rate I would guess 2 jelly rolls would make one to the bed frame.