Cycling speed calculator
Choose a gear and a wheel size, then enter your cadence to see how fast you ride - or enter the speed you want and see how fast you must pedal in that gear.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Choose whether to find the speed or the cadence, and the units.
- Enter the chainring and sprocket teeth and pick the tyre size (or a measured circumference).
- Enter your cadence, or the speed you want to hold.
How it works
Development (m) = chainring ÷ sprocket × wheel circumference. Speed in km/h = development × rpm × 60 ÷ 1000. Cadence for a target speed is the same relation solved for rpm: speed × 1000 ÷ 60 ÷ development. Miles per hour use 1 mile = 1.609344 km.
Worked example
A 50×17 gear on a 700×25C tyre (2.105 m) has a development of 6.19 m. At 90 rpm that is 6.19 × 90 × 60 ÷ 1000 = 33.4 km/h. To hold 20 mph (32.19 km/h) in a 52×13 gear (development 8.42 m) you need 32.19 × 1000 ÷ 60 ÷ 8.42 = 63.7 rpm.
Tips
Tyre sizes are typical values and accurate to about one percent. See the whole gearing of your bike, including gear inches, in the bicycle gear calculator.
Frequently asked questions
How is cycling speed calculated from cadence?
Speed equals the distance covered per pedal turn times the number of turns per minute. That distance - the development - is the chainring-to-sprocket ratio times the wheel circumference.
What cadence is normal?
Many road cyclists pedal at roughly 80 to 100 rpm, while touring and climbing cadences are often lower. The calculator does not judge it; it shows what a given cadence means in speed.
Why does my bike computer show a different speed?
The computer uses the wheel circumference you entered, and real rolling circumference changes with tyre pressure and rider weight. Also, this calculator assumes no wheel slip and a steady cadence in a single gear.
How do I find my wheel circumference?
Mark the tyre and the floor, roll the bike forward one full wheel turn with you on it, and measure the distance in millimetres. Choose "Custom circumference" and enter it.