Question: how to calculate how much fabric you need for quilt backing?
Answer: The amount of yardage needed is rounded up to the nearest eighth of a yard. For example, suppose the backing you need for a quilt is 52 inches wide by 96 inches long and the fabric you wish to use for the backing is on a bolt of fabric whose width is 43 inches. The yardage required is 5 1/3 yards.