A small tool for thoughtful sewing
Fabric shrinkage
calculator.
Turn a washed swatch into a clearer fabric plan. Measure the change, work out your yardage, and keep a record for the next cut.
01 / Measure your swatch
Example values loadedMeasure the same length and width before and after washing and drying. Replace the sample values with your own.
Calculated on your device. Measurements are never sent to us. Need a measuring guide?
20 × 20 cm → 19 × 19.4 cm
Area change: 7.85% shrinkage
This describes one measured sample. Repeated washing and a different batch can give different results.
Measure first. Cut with a clearer plan.
The complete measuring guide ↗Mark a sample.
Identify length and width. Mark reference distances within the cloth so fraying edges do not become your measuring points.
Wash, dry, measure.
Follow the fabric’s care instructions. Measure between the same marks with the sample relaxed and fully dry.
Record both directions.
Use lengthwise change to plan length. Check width separately against your cutting layout, then keep a record with your swatch.
02 / Plan your fabric length
Enter the length you need after washing and the lengthwise rate from your sample. Example: keep 2 metres with 5% shrinkage.
Extra length is optional. Check whether your pattern already includes an allowance to avoid counting it twice.
2.25 m
Rounded up to the next 0.25 m shop increment.
Estimated length after washing: 2.1375 m
Check the usable width and your pattern layout separately. More length cannot fix fabric that becomes too narrow.
An estimate assuming the sample rate repeats across the length. Read the method and limits.
A little maths, made tangible.
All worked examples ↗Before you cut
How is fabric shrinkage calculated?
Subtract the after-wash measurement from the before-wash measurement, divide by the before-wash measurement, then multiply by 100. A marked distance that changes from 20 cm to 19 cm has 5% shrinkage. Calculate length and width separately.
Can I use inches instead of centimetres?
Yes. The percentage is independent of the unit when both measurements use the same unit. The unit selector converts all four existing measurements. The length planner has separate metres and yards.
What if my fabric grows?
A larger after-wash measurement is shown as growth. This can happen in one direction while the other shrinks. Check that the sample is relaxed and the same reference marks were measured. Do not rely on one growth result to buy less cloth.
Is there a standard shrinkage percentage for cotton or linen?
This tool does not assume one. Construction and processing matter as well as fibre. Cotton Incorporated’s CottonWorks guide explains the factors behind dimensional change. Measure the fabric you intend to use.
Does this tell me whether my garment will fit?
No. It measures dimensional change in a sample, not garment fit, seam behaviour, skew, colour changes or pattern suitability. The yardage estimate does not optimise a cutting layout.
Fabric / batch: _______________________________________________
Care process / drying / cycles: __________________________________
Measured on: __________________ Notes: ________________________
https://swatch-ledger.pages.dev · Sample-based estimate; check usable width and pattern layout.