Fabric Shrinkage Allowance Calculator

Work out fabric shrinkage allowance instantly with clear inputs, formula shown and shareable results.

About Fabric Shrinkage Allowance Calculator

To finish at a target dimension after shrinkage, the cut dimension must be the finished value divided by (1 - shrinkage fraction), not multiplied by (1 + shrinkage). The distinction matters: 5% shrinkage needs a 5.26% allowance, and the error compounds across both directions in area terms.

Formula

Shrinkage allowance

Cut dimension = finished dimension / (1 - shrinkage %)

Worked example

With the default values below, Fabric Shrinkage Allowance Calculator returns Cut Length Required of 104.167. Change any input above and every figure here is recalculated in your browser.

Inputs used

Required Finished Dimensionminimum 0.001 cm: 100 cm
Lengthwise Shrinkageaccepts -20–40 %: 4 %
Widthwise Shrinkageaccepts -20–40 %: 2.5 %
Required Finished Widthminimum 0.001 cm: 50 cm

Results

Cut Length Required: 104.167
Cut Width Required: 51.282
Length Allowance Added: 4.167
Extra Fabric Needed: 6.838%

Step by step

1Values used
2Shrinkage allowance
3Cut Length Required= 104.167
4Cut Width Required= 51.282
5Length Allowance Added= 4.167
6Extra Fabric Needed= 6.838

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why divide rather than multiply?

Shrinkage is measured as a loss from the original size. Adding 5% to the finished size then losing 5% of that larger figure leaves you short — the correct inverse is division.

How is shrinkage measured?

By marking a known distance on the fabric, laundering to the specified standard, then re-measuring. Test both directions and after multiple wash cycles, since much shrinkage occurs in the first two washes but not all.