Band Stretch Calculator

Calculate measured stretch factor from relaxed and stretched band lengths.

This tool calculates only the measured stretch ratio of a band from your own lengths. It does not recommend a target stretch factor for any rubber or setup.

Calculator

Units
Length between the relevant tying/connection points when the rubber is not stretched.
Length of the same rubber section while stretched in the measured setup.
Optional reference for neutral comparison only.

Result

Actual stretch factor: —

Relaxed length
Stretched length
Selected unit
Manufacturer specification
Difference (actual - manufacturer)

How this works

The stretch factor is calculated as: 

R = L1 / L0
  • R — stretch factor
  • L0 — relaxed rubber length
  • L1 — stretched rubber length

3.0× means stretched length is 300% of relaxed length.

Compare this measurement with the instructions supplied by the manufacturer.

For terminology and ratio interpretation, read Speargun Band Stretch Factor Explained.

If you need to estimate a working rubber length after selecting a manufacturer ratio, continue to the Speargun Band Length Calculator.

Reference tool only. Always follow your equipment manufacturer's specifications; SpearMetric does not guarantee compatibility.