Crank Length Calculator

Crank length is the distance from the center of the bottom bracket axle to the center of the pedal spindle hole. It directly affects how your legs move through each pedal stroke and influences power output, cadence, and joint stress.

Most production bikes come with 170mm or 172.5mm cranks, but this one-size-fits-most approach leaves many riders with suboptimal crank lengths. Riders with shorter or longer legs benefit significantly from properly sized cranks that match their individual biomechanics. Crank length works alongside saddle and cockpit setup — our complete bike fitting guide walks through the full process.

When changing crank length, always re-adjust your saddle height. A longer crank effectively raises your pedal's lowest point, so raise your saddle by the same amount of change (e.g., going from 170mm to 175mm means raising the saddle 5mm).

Allow 2-3 weeks of gradual riding to adapt to a new crank length. Your muscles and pedaling neuromuscular patterns need time to adjust. Start with shorter, easier rides before returning to your normal training intensity.