Elastic Cut Length Calculator

Elastic Cut Length Calculator: Cut for a Snug, Not Sloppy, Fit

Elastic needs to be cut shorter than the body measurement it will sit against, since it stretches to fit; cutting it to the exact body measurement leaves it loose. This calculator applies a standard reduction percentage to get the right cut length.

The Formula

Elastic Length = Body Measurement × (1 − Reduction% / 100)

Worked Example

A 30" waist measurement, with a standard 10% reduction.

Elastic Length = 30 × 0.90 = 27 inches

How to Use This Calculator

1. Enter the body measurement the elastic will sit against.
2. Optionally adjust the reduction percentage (10-20% is typical, depending on desired snugness).
3. Click Calculate to get the elastic length to cut.

Related Calculations

Use with the Gathering/Ruffle Ratio Calculator when the same waistband also needs gathered fabric.