Cycling Power Calculator
Estimate the watts required to ride at a given speed, weight, and gradient using cycling physics.
By Jonas Lindemann · Updated · How we build our calculators
Rider + bike
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Calculation Method
Cycling Power Calculator
This calculator estimates the power in watts you need to ride at a given speed, weight, and gradient, using the same physics model that powers cycling speed tools.
The Power Model
Power is the sum of three forces you overcome: rolling resistance, aerodynamic drag (which rises with the cube of speed), and gravity on a climb, all divided by drivetrain efficiency.
Watts per Kilogram
Dividing power by weight gives watts per kilogram, the key metric for climbing. Recreational riders sustain about 2 to 3 W/kg at threshold, while pros reach 5.5 to 6.5 W/kg.
Frequently Asked Questions
Power is the sum of the forces you overcome multiplied by your speed: rolling resistance, aerodynamic drag (which rises with the cube of speed), and gravity on any incline, all divided by drivetrain efficiency. This calculator uses standard road-cycling constants.
On flat ground a typical rider needs roughly 180 to 250 watts to hold 20 mph (32 km/h), depending on weight, position, and equipment, because aerodynamic drag dominates at that speed.
Recreational riders often sustain about 2 to 3 W/kg at threshold, strong amateurs 3.5 to 4.5 W/kg, and professionals 5.5 to 6.5 W/kg. Higher power-to-weight is a major advantage on climbs.