Fabric Shrinkage & Purchase Length

When to use it

Measure the same marked sample before and after washing, drying and finishing as intended. Enter the required length after prewashing and the supplier’s selling increment. The example is metric; the usable width must also fit your pattern layout.

Example prices in USD; replace them with your own quotes. All dimensions use metric units.

Related calculation: Fabric Weight & Price.

Inputs

USD

Calculation method

Each shrinkage rate is 1 − after/before. Divide required length by the length retention ratio, then round up to the purchase increment. Multiply purchased length and raw width by their respective retention ratios. The example gives 5% length shrinkage and 2% width shrinkage: buy 3.2 m for 3.04 m usable length and 1.47 m usable width.

1-47.5 [Length after cm]/50 [Length before cm] → Length shrinkage

1-49 [Width after cm]/50 [Width before cm] → Width shrinkage

3 [Needed length m]/(1-Length shrinkage) → Minimum length m

ceil(Minimum length m/0.1 [Buy step m]) × Buy step m → Buy length m

Buy length m × (1-Length shrinkage) → Usable length m

1.5 [Raw width m] × (1-Width shrinkage) → Usable width m

Buy length m × 12 [Price per metre USD/m] → Fabric cost USD

Change one input

Change the sample’s washed length from 47.5 to 45 cm. Length shrinkage becomes 10%; buying 3.4 m yields 3.06 m. Width is unchanged.

Results are displayed to at most two decimal places; later formulas use unrounded values.

Scope and limits

• Measure both directions under the intended wash conditions.
• Buy length is rounded up to the selling increment.
• Check usable width separately; no pattern layout.

All dimensions and the purchase increment must be positive; price may be zero. Washed dimensions must not exceed the original dimensions in this shrinkage-only model. Measurements need to represent the fabric batch and treatment. No seam allowance, selvage loss, pattern matching or cutting layout is calculated. Purchasing more length cannot automatically solve insufficient width.

Sources

Download and import into Calvance to edit the numbers. The canvas does not reject every invalid input; check the stated ranges.

Common questions

Is adding 5% enough for 5% shrinkage?

No. Divide the target length by 0.95; multiplying it by 1.05 does not fully compensate.

Is shrinkage fixed for cotton or linen?

No. Test your material and intended treatment instead of assuming a universal rate.

How to import your template

We recommend using the latest version of Calvance.

1. Save the file. Choose Download template and save the .calvx file to Files on your iPhone or iPad. From a computer, you can send it to your device with AirDrop.
2. Open Import. In All Canvases in Calvance, tap the add button to open the template screen, then choose Import.
3. Choose the file. Select the saved .calvx file to create your own canvas. Importing uses one canvas from your allowance.
4. Edit and check. Check the results against the worked example, then add your numbers. Duplicate the canvas to keep different versions.

Download .calvx file