Fabric Shrinkage Calculator
Measure a long run rather than 10 cm. If 100 cm comes back as 96, shrinkage is 4%. To be left with 200 cm after washing you need 200 ÷ 0.96 = 208.3 cm, so 8.3 cm goes in the wash. Adding 4% instead gives 208 cm, which is slightly short — the correct step is to divide, not to add.
Your numbers
Shrinkage
4%
Fabric needed
208.3cm
Extra to buy
8.3cm
Formula
Shrinkage = (Before washing − After washing) ÷ Before washing × 100, Fabric needed = Finished length ÷ (1 − Shrinkage ÷ 100)
Cotton and linen lose 3–10% on the first wash and denim more. Width shrinks as well, so check that separately when a piece only just fits across. Pre-washing before you cut removes the guesswork entirely.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Before washing (cm)The measurement before washing. | 100 | 1 and up |
| After washing (cm)The same measurement after washing. | 96 | 1 and up |
| Finished length (cm)The length when finished. | 200 | 1 and up |
Step by step
Quick reference table
Results when only Before washing (cm) changes and everything else stays put.
| Before washing (cm) | Shrinkage (%) | Fabric needed (cm) | Extra to buy (cm) |
|---|---|---|---|
| 50 | -92 | 104.2 | -95.8 |
| 75 | -28 | 156.3 | -43.7 |
| 100 | 4 | 208.3 | 8.3 |
| 150 | 36 | 312.5 | 112.5 |
| 200 | 52 | 416.7 | 216.7 |
What each result means
| Result | At default values |
|---|---|
| Shrinkage (%)How much it shrank; pre-washing spends this before you cut. | 4 |
| Fabric needed (cm)Fabric length to buy, along the grain rather than across. | 208.3 |
| Extra to buy (cm)The extra to buy so shrinkage does not leave you short. | 8.3 |
Common mistakes
Cotton and linen lose 3–10% on the first wash and denim more. Width shrinks as well, so check that separately when a piece only just fits across. Pre-washing before you cut removes the guesswork entirely.
Glossary
- Before washing
- The measurement before washing.
- After washing
- The same measurement after washing.
- Finished length
- The length when finished.
- Shrinkage
- How much it shrank; pre-washing spends this before you cut.
- Fabric needed
- Fabric length to buy, along the grain rather than across.
- Extra to buy
- The extra to buy so shrinkage does not leave you short.
Frequently asked questions
Q. How is Fabric Shrinkage Calculator calculated?
Shrinkage = (Before washing − After washing) ÷ Before washing × 100, Fabric needed = Finished length ÷ (1 − Shrinkage ÷ 100) — Measure a long run rather than 10 cm. If 100 cm comes back as 96, shrinkage is 4%. To be left with 200 cm after washing you need 200 ÷ 0.96 = 208.3 cm, so 8.3 cm goes in the wash. Adding 4% instead gives 208 cm, which is slightly short — the correct step is to divide, not to add.
Q. Can you walk through an example?
With Before washing 100cm, After washing 96cm, Finished length 200cm, the answer is Shrinkage 4%.
Q. What do I need to enter?
Enter Before washing, After washing, Finished length. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Before washing (cm) moves the answer to Before washing (cm) 50 → Shrinkage (%) -92 and Before washing (cm) 200 → Shrinkage (%) 52. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Cotton and linen lose 3–10% on the first wash and denim more. Width shrinks as well, so check that separately when a piece only just fits across. Pre-washing before you cut removes the guesswork entirely.
Related calculators
Materials differ in density and absorption. If your label states a figure, use it — the defaults here are only common values.