Bike Cadence and Speed Calculator
Enter your target speed, chainring and cog teeth, and wheel size to instantly see the cadence (RPM) you need to pedal in that gear — plus a full cadence–speed curve so you can compare gears.
km/h
teeth
teeth
Wheel size
Pedal revolutions per minute needed to reach the target speed in this gear
- 1
Gear ratio
50 ÷ 17 = 2.941 - 2
Gear development
2.941 × 2,096 ÷ 1 000 = 6.165Distance (m) the bike travels per complete pedal revolution. - 3
Required cadence
25 × 1 000 000 ÷ (2.941 × 2,096 × 60) = 67.6
How does this calculator work?
Required cadence equals target speed in km/h multiplied by 1 000 000, divided by gear ratio times wheel circumference in mm times 60. At 25 km/h with a 50/17 gear on a 700×25c wheel the answer is about 67.8 RPM. The built-in curve shows speed at every cadence from 40 to 150 RPM.
Formula
How this is calculated
The relationship between cycling speed, cadence and gearing is a single linear equation: speed is directly proportional to cadence and to the gear ratio. Rearranging gives the cadence required for any target speed as: cadence = speed_kmh × 1 000 000 ÷ (gear_ratio × wheel_circ_mm × 60). The gear ratio is simply the number of chainring teeth divided by the number of cog teeth on the rear cassette; a 50/17 ratio means the rear wheel turns 2.94 times for every pedal revolution.
Gear development is the distance the bike travels per pedal revolution: gear ratio × wheel circumference. A development of 6.16 m means that at 90 RPM you travel 6.16 × 90 = 554 m per minute, or about 33.3 km/h. The cadence–speed curve plots this linear relationship across the full cadence range (40–150 RPM), showing you at a glance how changing cadence shifts your speed in that gear.
All calculations assume perfectly flat ground and no wheel slip. Different gear combinations can produce the same speed at different cadences — a higher gear demands lower RPM for the same speed, and vice versa. The wheel circumference presets are typical values; measure your actual tyre if you need precision.
Frequently asked questions
Speed (km/h) = cadence (RPM) × gear ratio (chainring ÷ cog) × wheel circumference (mm) × 60 ÷ 1 000 000. At 90 RPM with a 50/17 gear on a 700×25c wheel, that is 90 × 2.94 × 2096 × 60 ÷ 1 000 000 ≈ 33.3 km/h.
Most road cycling coaches recommend 80–100 RPM for sustained efforts. A higher cadence in a lighter gear generally reduces muscular fatigue and knee stress compared with turning a big gear at low RPM, though individual optimal cadence varies with fitness and terrain.
Every gear change shifts the entire cadence–speed line up or down. Moving to a bigger chainring or smaller cog increases the gear ratio, so the same cadence produces higher speed — or you need fewer RPM to hold the same speed. The curve in this calculator updates instantly when you change the gear teeth.
Also known as
TG we-Calculate Editorial Team. (2026). Bike Cadence and Speed Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/bike-cadence-and-speed-calculator
TG we-Calculate Editorial Team. "Bike Cadence and Speed Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/bike-cadence-and-speed-calculator.
TG we-Calculate Editorial Team, "Bike Cadence and Speed Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/bike-cadence-and-speed-calculator
@misc{wecalculate_bike_cadence_and_speed_calculator, title = {Bike Cadence and Speed Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/bike-cadence-and-speed-calculator}}, year = {2026}, note = {TG we-Calculate} }
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