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POWER & PERFORMANCE

Gear Ratio
Calculator v1.0

Calculate your gear ratio, speed and development from chainring, sprocket, wheel size and cadence. Adjust the inputs to compare setups in real time.

Inputs
50T
17T
mm
Presets: 700×23c · 700×25c · 700×28c
90 rpm
Results
Gear Ratio
2.94
50T / 17T
Speed 33.3 km/h
Speed (mph) 20.7 mph
Development 6.19 m/rev
Speed Table
Cadence (rpm) Speed (km/h) Speed (mph)
Formulae

Gear Ratio = Chainring teeth ÷ Sprocket teeth
Development = Gear Ratio × Wheel Circumference / 1000  (metres per pedal revolution)
Speed (km/h) = Gear Ratio × Circumference (mm) × Cadence (rpm) × 60 ÷ 1,000,000
Speed (mph) = Speed (km/h) ÷ 1.60934
Changelog: v1.0 — Initial release. Chainring and sprocket combinations to speed at any cadence, with development and gear inches.