Use our free Quilt Backing Calculator to determine the precise amount of fabric yardage required for your next quilting project. Simply input your quilt top dimensions, desired overhang, and backing fabric width, and let our tool instantly calculate your needs. Avoid buying too little or too much fabric!
Formula:
The calculator determines the total backing dimensions (Quilt Top Length + 2 × Overhang, and Quilt Top Width + 2 × Overhang). It then evaluates two layout options (fabric strips running parallel to quilt length or parallel to quilt width) against your specified Backing Fabric Width to find the most fabric-efficient method. Finally, it converts the minimum required fabric length to yards and adds any specified extra percentage for safety.
Simplified, the core idea is:
Required Fabric Length (inches) = (Quilt Top Dimension + 2 × Overhang) × Number of Strips
Where Number of Strips = ceil((Opposite Quilt Top Dimension + 2 × Overhang) / Fabric Width) for the chosen layout.