Bike speed from cadence, gear and wheel
While you are pedaling and not coasting, the chain ties the wheel to the cranks, so speed is not an estimate: it is geometry. One turn of the pedals moves the bike by the development, wheel circumference × chainring teeth ÷ cog teeth. Speed = development × cadence. With the development in meters and the cadence in revolutions per minute, speed in km/h = development × cadence × 60 ÷ 1000.
Turned round, the cadence for a speed = speed ÷ development. This is the useful direction when you choose gears: pick the speed you want to hold, and see whether the cadence it needs in a given gear is one you can keep up. One of the sources puts most riders between eighty and a hundred revolutions per minute on the flat.
The only uncertain part is the wheel. A circumference worked out from the tire marking can be a percent or two off, and the speed is off by the same share. If you have measured the roll-out of your wheel, or trust the wheel size set in your bike computer, enter that instead.
The formula says nothing about whether you can produce the power. Air resistance grows quickly with speed, so the top rows of the charts below are reached downhill or in a sprint.
Bike speed at cadence chart: big chainring, by cog and cadence
Each cell is the speed for the cog in its row at the cadence in its column, in revolutions per minute. Chainring = 50 teeth; wheel = a 28-622 tire (700 × 28C).
| Cadence, pedal turns per minute | |||||||
|---|---|---|---|---|---|---|---|
| Cog teeth | 60 | 70 | 80 | 90 | 100 | 110 | 120 |
| 11 | 34.9 km/h | 40.7 km/h | 46.5 km/h | 52.3 km/h | 58.1 km/h | 63.9 km/h | 69.7 km/h |
| 12 | 31.9 km/h | 37.3 km/h | 42.6 km/h | 47.9 km/h | 53.2 km/h | 58.6 km/h | 63.9 km/h |
| 13 | 29.5 km/h | 34.4 km/h | 39.3 km/h | 44.2 km/h | 49.2 km/h | 54.1 km/h | 59.0 km/h |
| 14 | 27.4 km/h | 31.9 km/h | 36.5 km/h | 41.1 km/h | 45.6 km/h | 50.2 km/h | 54.8 km/h |
| 15 | 25.6 km/h | 29.8 km/h | 34.1 km/h | 38.3 km/h | 42.6 km/h | 46.9 km/h | 51.1 km/h |
| 16 | 24.0 km/h | 28.0 km/h | 31.9 km/h | 35.9 km/h | 39.9 km/h | 43.9 km/h | 47.9 km/h |
| 17 | 22.6 km/h | 26.3 km/h | 30.1 km/h | 33.8 km/h | 37.6 km/h | 41.3 km/h | 45.1 km/h |
| 19 | 20.2 km/h | 23.5 km/h | 26.9 km/h | 30.3 km/h | 33.6 km/h | 37.0 km/h | 40.4 km/h |
| 21 | 18.3 km/h | 21.3 km/h | 24.3 km/h | 27.4 km/h | 30.4 km/h | 33.5 km/h | 36.5 km/h |
| 23 | 16.7 km/h | 19.4 km/h | 22.2 km/h | 25.0 km/h | 27.8 km/h | 30.6 km/h | 33.3 km/h |
| 25 | 15.3 km/h | 17.9 km/h | 20.4 km/h | 23.0 km/h | 25.6 km/h | 28.1 km/h | 30.7 km/h |
| 28 | 13.7 km/h | 16.0 km/h | 18.3 km/h | 20.5 km/h | 22.8 km/h | 25.1 km/h | 27.4 km/h |
| 30 | 12.8 km/h | 14.9 km/h | 17.0 km/h | 19.2 km/h | 21.3 km/h | 23.4 km/h | 25.6 km/h |
| 32 | 12.0 km/h | 14.0 km/h | 16.0 km/h | 18.0 km/h | 20.0 km/h | 22.0 km/h | 24.0 km/h |
| 34 | 11.3 km/h | 13.2 km/h | 15.0 km/h | 16.9 km/h | 18.8 km/h | 20.7 km/h | 22.6 km/h |
Work out your own numbers: Bike cadence and speed calculator
Bike speed at cadence chart: small chainring, by cog and cadence
The same cassette on the small ring of a compact crankset. Chainring = 34 teeth; wheel = a 28-622 tire (700 × 28C).
| Cadence, pedal turns per minute | |||||||
|---|---|---|---|---|---|---|---|
| Cog teeth | 60 | 70 | 80 | 90 | 100 | 110 | 120 |
| 11 | 23.7 km/h | 27.7 km/h | 31.6 km/h | 35.6 km/h | 39.5 km/h | 43.5 km/h | 47.4 km/h |
| 12 | 21.7 km/h | 25.3 km/h | 29.0 km/h | 32.6 km/h | 36.2 km/h | 39.8 km/h | 43.5 km/h |
| 13 | 20.1 km/h | 23.4 km/h | 26.7 km/h | 30.1 km/h | 33.4 km/h | 36.8 km/h | 40.1 km/h |
| 14 | 18.6 km/h | 21.7 km/h | 24.8 km/h | 27.9 km/h | 31.0 km/h | 34.1 km/h | 37.2 km/h |
| 15 | 17.4 km/h | 20.3 km/h | 23.2 km/h | 26.1 km/h | 29.0 km/h | 31.9 km/h | 34.8 km/h |
| 16 | 16.3 km/h | 19.0 km/h | 21.7 km/h | 24.4 km/h | 27.2 km/h | 29.9 km/h | 32.6 km/h |
| 17 | 15.3 km/h | 17.9 km/h | 20.4 km/h | 23.0 km/h | 25.6 km/h | 28.1 km/h | 30.7 km/h |
| 19 | 13.7 km/h | 16.0 km/h | 18.3 km/h | 20.6 km/h | 22.9 km/h | 25.2 km/h | 27.4 km/h |
| 21 | 12.4 km/h | 14.5 km/h | 16.6 km/h | 18.6 km/h | 20.7 km/h | 22.8 km/h | 24.8 km/h |
| 23 | 11.3 km/h | 13.2 km/h | 15.1 km/h | 17.0 km/h | 18.9 km/h | 20.8 km/h | 22.7 km/h |
| 25 | 10.4 km/h | 12.2 km/h | 13.9 km/h | 15.6 km/h | 17.4 km/h | 19.1 km/h | 20.9 km/h |
| 28 | 9.3 km/h | 10.9 km/h | 12.4 km/h | 14.0 km/h | 15.5 km/h | 17.1 km/h | 18.6 km/h |
| 30 | 8.7 km/h | 10.1 km/h | 11.6 km/h | 13.0 km/h | 14.5 km/h | 15.9 km/h | 17.4 km/h |
| 32 | 8.1 km/h | 9.5 km/h | 10.9 km/h | 12.2 km/h | 13.6 km/h | 14.9 km/h | 16.3 km/h |
| 34 | 7.7 km/h | 8.9 km/h | 10.2 km/h | 11.5 km/h | 12.8 km/h | 14.1 km/h | 15.3 km/h |
Work out your own numbers: Bike cadence and speed calculator
Chart: cadence needed for a speed, by speed and cog
Each cell is the cadence in revolutions per minute that holds the speed in its row on the cog in its column. Chainring = 50 teeth; wheel = a 28-622 tire (700 × 28C).
| Cog teeth | |||||||
|---|---|---|---|---|---|---|---|
| Target speed | 11 | 13 | 15 | 17 | 19 | 21 | 24 |
| 20 km/h | 34 | 41 | 47 | 53 | 59 | 66 | 75 |
| 25 km/h | 43 | 51 | 59 | 67 | 74 | 82 | 94 |
| 30 km/h | 52 | 61 | 70 | 80 | 89 | 99 | 113 |
| 35 km/h | 60 | 71 | 82 | 93 | 104 | 115 | 131 |
| 40 km/h | 69 | 81 | 94 | 106 | 119 | 131 | 150 |
| 45 km/h | 77 | 92 | 106 | 120 | 134 | 148 | 169 |
| 50 km/h | 86 | 102 | 117 | 133 | 149 | 164 | 188 |
Work out your own numbers: Bike cadence and speed calculator
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- Bike cadence and speed calculatorSpeed from cadence, and cadence from speed, for one gear.