Bicycle Chain Length & Derailleur Pulley Calculator

Calculate your precise drivetrain requirements for optimal shifting performance and component safety.

Drivetrain Inputs

mm

Recommended

Links Required
Optimal Configuration

Measurement Guide

Chainstay Length

How to get accurate measurements

1

Measure the Chainstay

Measure from the center of the bottom bracket axle to the center of the rear wheel axle in millimeters.

2

Verify Teeth Count

Count the teeth on your largest chainring and your largest cassette cog accurately to ensure the calculator works correctly.

3

Check Safety

Always test your shifting after installing a new chain. If the derailleur cage is overly stretched in the largest gear, add links immediately.