How much extra backing should I add?
Many quilters add 4 inches on each side, though longarm quilters may request a specific amount.
Free quilting calculator
Quilt Backing Calculator
Estimate how much backing fabric you need before you visit the fabric store. This calculator uses inches and yards, with common U.S. quilting defaults like 4 inches of backing overage per side and 44 inch quilting cotton.
Result
Backing estimate
Buy about 4.5 yards of 44" fabric.
- Required backing size
- 68" × 80"
- Panels needed
- 2 panels
- Usable fabric width
- 43.5"
- Estimated yardage
- 4.5 yards
Round up when buying fabric, especially for directional prints, shrinkage, or cutting mistakes.
Formula
Backing size = quilt size + overage on both sides. Panel count = required backing width ÷ usable fabric width. Yardage = panel count × backing length ÷ 36.
Example calculation
For a 60" × 72" throw quilt with 4" extra on each side, the required backing size is 68" × 80". With 44" fabric, you usually need two panels.
Results are planning estimates. Always round up when buying fabric, especially for directional prints, shrinkage, fussy cutting, or cutting mistakes.
Related calculators
Quilt Binding CalculatorFind the binding length, number of WOF strips, and fabric yardage needed for your quilt binding.Quilt Batting CalculatorCalculate batting size for baby, throw, twin, queen, king, or custom quilts with extra overage on each side.Quilt Size CalculatorChoose a quilt type or enter custom dimensions to estimate finished quilt size, backing, batting, and binding needs.
Frequently asked questions
Can I use 108 inch fabric for quilt backing?
Yes. Wide backing fabric often reduces or removes the need to piece backing panels.
Should I round up backing yardage?
Yes. Fabric is usually bought in fractions of a yard, and rounding up helps cover trimming, shrinkage, and cutting mistakes.
Does this replace a quilt pattern?
No. It is a planning calculator for backing fabric, not a copyrighted quilt pattern.