Cycling Power Calculator
Estimate the power required to ride at a given speed.
About Cycling Power Calculator
Aerodynamic drag scales with the cube of speed, so it dominates on the flat above about 25 kilometres per hour. On climbs gravity takes over, which is why aerodynamics matters little uphill and enormously on the flat. Doubling speed on the flat requires roughly eight times the power, which is why small aerodynamic improvements translate into meaningful speed gains.
Formula
Cycling Power
Power = ½ρ·CdA·v³ + Crr·m·g·v + m·g·gradient·v, plus drivetrain loss
- CdA
- Drag area, the product of drag coefficient and frontal area
- cubic relationship
- Aerodynamic power rises with the cube of speed
Worked example
With the default values below, Cycling Power Calculator returns Power Required of 177.3. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Speedminimum 0.1 km/h
- 32 km/h
- Rider weightaccepts 20–200 kg
- 72 kg
- Bike weightaccepts 3–30 kg
- 9 kg
- Gradientaccepts 0–100 %
- 0 %
- Drag areaaccepts 0.15–0.8 m2
- 0.32 m2
- Rolling resistance coefficientaccepts 0.001–0.02
- 0.005
Results
- Power Required
- 177.3 W
- Power Overcoming Air Resistance
- 137.7 W
- Power Overcoming Rolling Resistance
- 35.3 W
- Power Overcoming Gravity
- 0.0 W
- Power to Weight Ratio
- 2.463 W/kg
Step by step
- 1Values used
- 2Cycling Power
- 3Power Required= 177.3 W
- 4Power Overcoming Air Resistance= 137.7 W
- 5Power Overcoming Rolling Resistance= 35.3 W
- 6Power Overcoming Gravity= 0.0 W
- 7Power to Weight Ratio= 2.463 W/kg
Assumptions and limits
- The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- These figures are estimates based on population-average formulas and are intended for training and recreational planning only. They are not medical advice. Consult a qualified health professional before starting or changing an exercise programme, particularly if you have an existing medical condition.
- This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
These figures are estimates based on population-average formulas and are intended for training and recreational planning only. They are not medical advice. Consult a qualified health professional before starting or changing an exercise programme, particularly if you have an existing medical condition.
Frequently Asked Questions
How is Cycling Power calculated?
Power = ½ρ·CdA·v³ + Crr·m·g·v + m·g·gradient·v, plus drivetrain loss Aerodynamic drag scales with the cube of speed, so it dominates on the flat above about 25 kilometres per hour. On climbs gravity takes over, which is why aerodynamics matters little uphill and enormously on the flat.
Why does Cycling Power matter?
Doubling speed on the flat requires roughly eight times the power, which is why small aerodynamic improvements translate into meaningful speed gains.
What values do I need to enter?
This calculator takes 6 inputs: Speed, Rider weight, Bike weight, Gradient, Drag area, Rolling resistance coefficient. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.