Understanding Bicycle Gear Ratios and Speed
Your cycling speed is determined by three factors: gear ratio, cadence, and wheel size. Gear ratio is simply the front chainring teeth divided by rear sprocket teeth. A high ratio (like 50/11 = 4.55) means each pedal stroke drives the wheel further, delivering high speed on flat ground but requiring significantly more force. A low ratio (like 34/32 = 1.06) is easy to pedal uphill but limits top speed.
Cadence — your pedaling rate in RPM — multiplies with gear ratio to determine final speed. At 80 RPM with a gear ratio of 3.0 on a 700c wheel, you'd travel about 30 km/h. Professional road cyclists maintain 80–100 RPM for efficiency; sustained high cadence reduces cumulative stress on knees compared to grinding large gears at low RPM.
Wheel size completes the equation. A 700c wheel has a circumference roughly 10% larger than a 26-inch MTB wheel, so it covers more ground per rotation at the same gear and cadence. Use this calculator to compare gear combinations, plan training ratios, or dial in the perfect fixie gear for your commute.
Frequently Asked Questions
For steep climbs, gear ratios between 1.0 and 2.0 work well. Mountain bikers often use sub-1.0 ratios (e.g., 28T/32T = 0.875) on technical ascents. Road cyclists rarely go below 1.5 on typical grades.
Development is the distance traveled per pedal revolution — what this calculator shows as "distance per revolution." It's a unit-agnostic way to compare gearing across bikes with different wheel sizes.
Absolutely. Enter your single chainring and cog tooth counts. Typical fixie ratios range from 2.0 to 3.0. City commuters often prefer 2.6–2.8 for a balance of climbing ability and flat-road speed.