By Zencalcy Editorial TeamLast reviewed About us
Estimate how fast you will travel at a given cadence, given your chainring, cassette cog, and wheel size. The calculator turns each crank turn into a distance and scales it by how fast you pedal. Choose a standard wheel size or enter your own measured circumference.
Estimate road speed from cadence, gearing, and wheel size.
speed (m/min) = cadence (rpm) × (chainring ÷ cog) × wheel circumference (m)
Wheel circumferences are typical values for a mounted tyre, so your exact figure depends on tyre width and pressure. Entering a measured rolling circumference is the most accurate route.
| Symbol | Meaning |
|---|---|
| cadence | How fast you turn the cranks, in revolutions per minute. |
| chainring | Teeth on the front chainring in use. |
| cog | Teeth on the rear cassette cog in use. |
| circumference | Rolling distance of one wheel turn, in metres. |
At 90 rpm with a 50 tooth chainring, a 16 tooth cog, and a 2.105 m circumference, the speed is 90 × 3.125 × 2.105 = 592 m per minute, which is about 35.5 km/h or 22.1 mph.
Road speed follows directly from how fast you turn the pedals, the gear you are in, and the size of the wheel. The relationship is speed equals cadence multiplied by gear ratio multiplied by wheel circumference, with cadence in revolutions per minute. Because the ratio is chainring teeth over cog teeth and the circumference is a fixed length, the only values the rider changes while moving are cadence and gear selection.
As a worked example, ninety revolutions per minute in a gear ratio of 3.5 with a wheel circumference of 2.1 metres gives 90 times 3.5 times 2.1, which is 661.5 metres per minute. Multiplying by sixty and dividing by a thousand converts that to about 39.7 kilometres per hour.
The formula assumes the cadence you enter is the actual chainring speed and that the wheel circumference matches your tyre and pressure. A larger tyre, lower pressure, or a loaded bike changes the rolling radius slightly, so the real speed drifts a little from the calculated figure.
It also ignores drivetrain losses and any wheel slip, both small on a bicycle, and it does not account for the fact that a speed is sustainable only if your power output matches the resistance at that speed. Use the number as the mechanical result of your gear and cadence, then check it against a power or heart rate estimate.
Continue with the Chain Length Calculator, Cycling Cadence Calculator, or the Cycling Power Calculator — or browse more cycling tools and all sports calculators.
Use a measured rolling circumference if you can. Otherwise pick the standard size that matches your wheel and tyre, and treat the result as an estimate.
Every result is computed locally in your browser from the formulas shown above. Nothing you type is uploaded, logged, or stored, and no account is required.
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Last reviewed: September 2026. See how we build and check every tool on the about page.
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Content updated: September 2026