Fabric Shrinkage Calculator
Shrinkage is the lost length divided by the original length. Measure both directions on the same sample to estimate the fabric size you need before washing.
No account needed. Calculations stay in your browser.
Enter values from 0 to 1,000,000,000. Positive measurements must be at least 0.001; stitch counts and repeats must be whole numbers.
- Width shrinkage (negative means growth)
- 5%
- Length shrinkage (negative means growth)
- 10%
- Starting size, before trim allowance
- 42.106 × 40 in
How the calculation works
Width shrinkage = (before width − after width) ÷ before width × 100. Calculate length shrinkage separately. Required starting dimension = target dimension × sample before ÷ sample after. A negative shrinkage result means that direction grew.
Worked example
A 10 × 10 inch sample that becomes 9.5 × 9 inches shrank 5% across and 10% along. To retain 40 × 36 inches, start with at least 42.106 × 40 inches under the same conditions. Add separate fabric for squaring and cutting.
Check before you start
This estimate uses your sample, not a standard shrinkage rate. Use the same fabric, wash and dry method for the sample and project. Measure a relaxed sample without pulling. A single wash cannot predict later washes. Add trimming, seam and print-matching allowances separately. Check the actual usable fabric before cutting.
These calculations use the dimensions you enter and the stated layout rules. They do not measure fabric shrinkage, yarn tension or your working pace.
Next steps
- How Much Fabric Do I Need for a Quilt?
- How Many Fat Quarters Do I Need for a Quilt?
- Quilt Binding and Backing Yardage Calculator Guide
- Open the quilt pattern generator
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