Chain Length Calculator

Large Chainring Teeth

Number of teeth on the largest front chainring

Largest Rear Cog Teeth

Number of teeth on the largest rear cassette cog

Chainstay Length (mm)

Distance from bottom bracket center to rear axle

Results

Calculated Length—

Rounded Up (even)—

Recommended Chain—

Formula: L = 2(C / 25.4) + (F/4 + R/4 + 1)
Where C = chainstay length in mm, F = front chainring teeth, R = rear cog teeth. Result is in links. Always round up to the nearest even number.