Quilt Backing Calculator

How the Quilt Backing calculator works

Formula. Needed width = quilt width + 4 inches. Needed length = quilt length + 4 inches. Yards = ceil(needed length / fabric width) × (needed width / 36).

Example. A 60 by 80 inch quilt on 42 inch fabric needs 64 by 84 inches. Yards are ceil(84 / 42) × (64 / 36) = 2 × 1.777... = 3.56 yards.

Limitation. The 4 inch allowance is fixed, and the piece count assumes strips of the fabric width with no matching of a directional print.