Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- No tire slip; use measured rollout for accuracy. Power, gradient, drag and whether that cadence is sustainable are not predicted.
Example Calculation
- Wheel rollout circumference: 2.1 m
- Front chainring teeth: 50
- Rear sprocket teeth: 25
- Cadence: 90 rpm
2.1 m wheel rollout with 50/25 gearing at 90 rpm gives 22.68 km/h.
Frequently asked questions
How do I use this calculator?
Enter wheel rollout circumference, front chainring teeth, rear sprocket teeth, cadence. The result updates automatically. Use Reset to restore the example values.
What method does it use?
speed km/h=circumference × front/rear × cadence ×60/1000.. No tire slip; use measured rollout for accuracy. Power, gradient, drag and whether that cadence is sustainable are not predicted.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.