Cycling Speed & Cadence Calculator
Work out your bike speed from cadence, chainring and sprocket teeth and wheel circumference — and see the gear ratio, gear inches and meters of development.
How fast a gear goes at a given cadence.
How the cycling speed & cadence calculator works
Every pedal revolution turns the rear wheel chainring ÷ sprocket times, and each wheel turn covers the wheel's circumference. Speed is therefore cadence × gear ratio × circumference. A 700×25c road tyre has a circumference of about 2,096 mm; check yours by rolling the bike one wheel turn and measuring.
Gear inches (wheel diameter in inches × ratio) and development (meters per pedal revolution) are the two traditional ways of comparing gears between bikes with different wheels; both are shown.
Formula: speed = cadence × (chainring ÷ sprocket) × circumference
Worked examples
| Inputs | Speed | Note |
|---|---|---|
| 50×17, 90 rpm, 700×25c | 33.3 km/h | about 33 km/h |
| 34×28 climbing gear, 75 rpm | 11.5 km/h | about 11.5 km/h |
| 53×11, 100 rpm | 60.6 km/h | a sprint gear: 60 km/h |
FAQFrequently asked questions
What cadence should I ride at?
Most riders settle between 80 and 95 rpm on the flat; climbing often drops to 70–80. Higher cadence shifts load from muscles to the cardiovascular system.
How do I measure wheel circumference?
Mark the tyre and the floor, roll the bike exactly one wheel turn with your weight on it, and measure the distance. Tyre size charts give close values if you cannot.
What are gear inches?
An old measure equal to the diameter of a penny-farthing wheel that would give the same distance per pedal turn: wheel diameter in inches × gear ratio. Around 100 is a big gear; 30 a small climbing one.
Does tyre width change the speed?
Slightly — a wider tyre has a larger circumference. The difference between 25 mm and 28 mm is about 2%.
Where these figures come from
- Riegel PS, "Athletic records and human endurance", American Scientist 1981 — T2 = T1 × (D2 ÷ D1)^1.06
- Cooper KH, "A means of assessing maximal oxygen intake", JAMA 1968 — the 12-minute run test
- Ainsworth BE et al., Compendium of Physical Activities (2024 update) — MET values by activity
- OpenPowerlifting — DOTS coefficients (Tim Konertz, 2019) — the DOTS polynomial used for scoring
- Naismith's rule (1892) as used by UK and Australian walking bodies — 1 hour per 5 km plus 1 hour per 600 m of ascent
- American College of Sports Medicine — exercize-science guidelines
Last checked: September 2026. Formulas are fixed by their published sources; the MET values come from the Compendium of Physical Activities.