Chain Length Calculator

Find the bike chain length from chainstay and gearing.

Chainstay length

Largest chainring teeth

Largest cog teeth

Chain length 53.5

Formula: L = 2·CS + (F/4 + R/4 + 1)

Step-by-step with your numbers:

1. Values used:

2. Chainstay length = 16.5

3. Largest chainring teeth = 50

4. Largest cog teeth = 28

6. Chain length = 53.5

Did we solve your problem today?

Sizing a chain correctly keeps shifting crisp and the derailleur safe.

The math behind it

The rigid-method formula: chain length = 2 × chainstay + (chainring teeth ÷ 4 + cog teeth ÷ 4 + 1) inches.

16.5" stay, 50T ring, 28T cog → about 52.5".

Round up or down?

Round up to the nearest whole link (chains adjust in pairs of half-links).