Bike Cadence and Speed Calculator

Enter your pedaling cadence, gear (chainring and cog teeth), and wheel circumference to find your riding speed, gear ratio, and distance per pedal stroke.

Quick Facts

Formula
Speed = cadence × (chainring ÷ cog) × wheel circumference
Each pedal turn advances the bike by the gear ratio times the wheel circumference (the "development").

Your Results

Calculated
Speed
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km/h
Speed
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mph
Gear ratio
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Chainring ÷ cog
Development
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Metres per pedal revolution

Ready

Enter your cadence, gear, and wheel size, then calculate.

About bike cadence and speed

Your speed on a bicycle is fixed by three things you fully control: how fast you spin the pedals (cadence), which gear you are in (the ratio of chainring teeth to rear-cog teeth), and how far the wheel rolls in one turn (its circumference). For a given gear and wheel, speed is directly proportional to cadence. This calculator turns those numbers into road speed, so you can see exactly how a gear change or a cadence change affects how fast you go.

The formula

Speed = cadence × gear ratio × wheel circumference, where gear ratio = chainring teeth ÷ cog teeth. The quantity gear ratio × wheel circumference is the development (also called rollout or metres of development): the distance the bike travels for one full turn of the pedals. Multiply development by cadence to get distance per minute, then convert to km/h or mph:

  • Development (m) = (chainring ÷ cog) × wheel circumference (m)
  • Distance per minute (m) = cadence (rpm) × development (m)
  • Speed (km/h) = distance per minute × 60 ÷ 1000
  • Speed (mph) = speed (km/h) ÷ 1.609344

Worked example: at 90 rpm in a 50×15 gear (ratio 3.33) on a 700×25c wheel (circumference 2.111 m), development is 3.33 × 2.111 = 7.04 m. Distance per minute is 90 × 7.04 = 633 m, so speed is 633 × 60 ÷ 1000 = 38.0 km/h (23.6 mph).

Reference wheel circumferences

Use your tire's rollout for accuracy. Common values: 700×23c ≈ 2096 mm, 700×25c ≈ 2111 mm, 700×28c ≈ 2136 mm, 700×32c ≈ 2155 mm, 26-inch MTB (26×2.0) ≈ 2074 mm, 27.5-inch (650b × 2.1) ≈ 2148 mm, 29-inch (29×2.2) ≈ 2302 mm. Tire pressure, actual width, and rider weight shift these by a few millimetres, so measuring your own rollout is the gold standard.

Cadence and gearing in practice

Most road cyclists pedal at 80–100 rpm; many pros hold 90–100 rpm on the flat and higher in a sprint. A higher cadence in an easier gear spins the legs faster but loads the muscles less; a lower cadence in a harder gear (a taller development) pushes more per stroke but raises muscular strain. For the same speed, spinning faster in a smaller gear generally spares the knees and is more aerobically efficient over long rides.

Frequently Asked Questions

How is bike speed calculated from cadence?
Speed equals cadence multiplied by gear ratio multiplied by wheel circumference. Each pedal revolution moves the bike forward by the gear ratio (chainring teeth divided by cog teeth) times the wheel circumference. Multiply that distance by your cadence in rpm to get distance per minute, then convert to km/h or mph. The relationship is exact for a chain-driven bike with no slip, so measurement precision on cadence and wheel size is what limits accuracy.
What wheel circumference should I use?
A 700x25c road tire is about 2111 mm; 700x23c about 2096 mm and 700x28c about 2136 mm. For mountain bikes, a 29er is roughly 2300 mm and a 26-inch wheel about 2074 mm. The most accurate method is to measure your own rollout: mark the tire and the ground, roll the bike forward exactly one wheel revolution with your weight on it, and measure the distance covered.
Does a higher cadence make me faster?
Not by itself. Speed depends on cadence and gear ratio together. Spinning faster in the same gear does increase speed, but you can reach the same speed with a lower cadence in a taller (harder) gear. Higher cadence in an easier gear shifts load from your muscles to your cardiovascular system, which many riders find more sustainable on long rides and easier on the knees.
What is gear development or rollout?
Development (rollout) is the distance the bike travels for one complete turn of the pedals, equal to the gear ratio times the wheel circumference. A 50x15 gear on a 700x25c wheel gives about 7.0 metres per pedal stroke. Comparing development across gear combinations is the cleanest way to judge whether one setup is taller or shorter than another, independent of cadence.

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