Quilt backing calculator
Plan backing panels from quilt size, usable fabric width, overhang and seam allowances, comparing both join directions.
Up to 1,000 equal full-width panels. Compares straight vertical and horizontal joins only. Offcut optimization, diagonal piecing, print matching and shrinkage need separate allowance. Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.
Your result
How to use Quilt backing calculator
- Enter your measurements, rates or supplied recipe.
- Review the quantities, rounding and plan details.
- Download the result and verify it against your actual materials or a sample.
Useful next steps
Add room beyond the quilt
Enter backing overhang on each edge and fabric width after removing selvedges. Each join consumes two seam allowances. Squaring allowance adds extra length to the purchase once, not once per panel.
Compare complete panel orientations
A 60 × 80 inch quilt with 4-inch overhang needs a 68 × 88 inch backing. With 42-inch usable width and half-inch seams, two panels with vertical joins cover the width. Cut each panel 88 inches long. Adding 2 inches for squaring gives 178 inches of fabric before purchase rounding.
Save the plan
Download the result as CSV, plus a text or JSON report with formulas, values and assumptions. Everything is calculated on your device. Changing units keeps the entered numbers, so check the selected units before using the plan.