Cycling Gear Ratio Calculator
Calculate bicycle gear ratios, development, and speed for any chainring and cassette combination.
Gear Ratio Analysis
Gear ratio in cycling determines how far you travel per pedal revolution. Higher gear ratios mean more speed but require more effort. Lower ratios make climbing easier.
The formulas:
Gear Ratio = Chainring Teeth / Cassette Teeth
Development (meters) = Gear Ratio x Wheel Circumference
Speed = Development x Cadence x 60 / 1000 (km/h)
Gear ratio explained:
- A ratio of 2.0 means the rear wheel turns twice for every pedal revolution.
- A ratio of 1.0 is a 1:1 ratio (one wheel turn per pedal turn).
- Ratios below 1.0 mean the wheel turns less than once per pedal revolution (very easy, for steep climbs).
Common chainring sizes:
- Road bike: 50/34 (compact), 52/36 (mid-compact), 53/39 (standard)
- Mountain bike: 30-34 (single), 26/36 (double)
- Gravel: 46/30, 48/31
Common cassette ranges:
- Road: 11-28, 11-30, 11-32, 11-34
- Mountain: 10-42, 10-46, 10-51, 10-52
Wheel circumference (700c road): approximately 2.10 meters (6.89 feet). For 26-inch mountain bike wheels: approximately 2.07 meters (6.79 feet). For 29-inch mountain bike wheels: approximately 2.30 meters (7.55 feet).
Cadence ranges:
- Climbing: 60-80 RPM
- Cruising: 80-90 RPM
- Racing: 90-110 RPM