Gear Ratio Calculator

Calculate gear ratios for any chainring and cog combination. Compare ratios across your cassette to find optimal gearing for your terrain.

Results

Visualization

How It Works

Gear ratio = chainring teeth / cog teeth. A ratio of 2.0 means the wheel turns twice per pedal revolution. Development is the distance traveled per pedal revolution — multiply ratio by wheel circumference. Gear inches is an older standard: ratio x 27 (the old wheel diameter). Higher ratios = harder to pedal but faster. Typical road range: 2.0 (climbing, 34/17) to 4.7 (sprinting, 53/11). MTB range: 0.8 (granny gear) to 3.8 (top gear). Modern 1x drivetrains use a single chainring with wide-range cassettes (10-52t).