Fabric Shrinkage Calculator
Enter the size of your fabric or the finished size you want, plus the shrinkage percentage. The calculator gives both the post-wash size and how much larger to cut.
Tip: use URL parameters to pre-fill, e.g. ?shrinkWidth=60&shrinkLength=80&shrinkPct=3.
How the calculation works
After washing, a piece shrinks by the percentage you enter: a 60-inch width at 3% shrinkage becomes about 58.2 inches. To end at 60 inches after the same wash, cut 60 divided by 0.97, or about 61.9 inches. The calculator does this in both directions for you.
The standard advice is to add 3-5% for quilting cotton, then confirm with a wash test on a scrap piece. Shrinkage varies by fiber, weave and how you dry the fabric.
What each input means
Target width / length: the size you want the piece to be after washing. For a quilt top, use your finished quilt size; for a single block, use the block size.
Shrinkage: the expected loss as a percentage. Use 0 for prewashed fabric, 2-3 for most cotton, and up to 5 for unwashed cotton or cotton blends.
Common questions
Should I add seam allowance on top of the shrinkage?
Yes. This calculator only handles shrinkage. For pieces that will be sewn, add the 1/4-inch seam allowance separately, or use the quilt block calculator first and then apply shrinkage.
What about flannel and linen?
Flannel and linen can shrink more than plain cotton — often 5-8% in the first wash. Test a scrap piece before cutting your whole project.
Do I need to worry about shrinkage after the quilt is finished?
Unwashed fabric in a finished quilt will shrink unevenly around the quilting, which can cause puckering. Prewashing the fabric or choosing prewashed fabric avoids most of this.