Bicycle gear calculator
Compare bicycle gearing, gear inches, development and cadence across your chainrings and cassette.
Use 1 to 32 space-separated tooth counts per list, whole counts from 1 to 1000, circumference from 100 to 10000 mm, cadence from 0 to 300 RPM and target speed from 0 to 2000 in the selected unit. Up to 1024 combinations. Decimal inputs allow up to six places. These are software bounds, not vehicle capability claims. Results use floating-point arithmetic. Processing stays on your device, with a bounded worker and a 10-second timeout. Full JSON and CSV preserve every calculated row and the assumptions. Do not use thousands separators. Up to 1,000,000 characters. Review the settings before running.
Your result
How to use Bicycle gear calculator
- Enter your chainring and sprocket tooth counts, separated by spaces.
- Enter measured rolling circumference, cadence and a target speed.
- Compare the paginated gear table. Download all combinations in JSON or CSV.
Useful next steps
Compare all gearing combinations
Development is rolling wheel circumference multiplied by chainring teeth divided by sprocket teeth. Speed is development multiplied by pedal revolutions per second. Gear inches divide development by pi and convert the equivalent diameter to inches.
Use rolling circumference
Measure one wheel revolution under the relevant load. Nominal tire markings do not provide an exact rolling circumference. Equal-ratio gear combinations remain distinct in the comparison. Mechanical compatibility and required riding effort are not evaluated.