This cycling calculator converts cadence and road speed using wheel rollout and drivetrain gear ratio.
Sports
Bike Cadence and Speed Calculator
Convert bicycle cadence and road speed from wheel size and drivetrain tooth counts.
Calculator
About this calculator
Formula notes
effective diameter = rim + 2 x tire height; rollout = pi x effective diameter; speed = rollout x gear ratio x cadence / 60.
Worked examples
- Example: a 622 mm rim with a 28 mm tire and 50/17 gearing at 90 RPM gives about 10.01 m/s, roughly 36.0 km/h.
- A 700c wheel with a 25 mm tire and 52/16 gearing at 100 RPM rides about 12.6 m/s, roughly 45.4 km/h.
How to use it
- Enter rim diameter, tire height, chainring teeth, and cog teeth.
- Choose whether you know cadence or speed.
- Read the effective diameter, rollout, gear ratio, cadence, and speed.
Frequently asked questions
Which direction can I solve?
You can solve for cadence from a known speed, or speed from a known cadence, by choosing the known value.
Does this include rider weight or drag?
No. The calculator is purely kinematic: wheel size and gear ratio determine the relationship.
Limits and interpretation
- The model assumes a rigid wheel circumference from rim and tire dimensions; real tire deformation and pressure change rollout slightly.
- It is kinematic only and ignores aerodynamics, gradient, drivetrain losses, and rider power.