Cycling Power (Watt) Calculator
Estimate cycling power output (watts) from speed, grade and rider weight.
Input Data
Metric or imperial.
Speed
Watt
Grade
Weight
Results
Estimated power in watts.
92
Explanatory note about the result.
25 km/h、總重 80kg、坡度 0% → 約 92 W。
At a glance:Power = drag + rolling + gravity terms: P = (0.5·ρ·Cd·A·v³) + Crr·m·g·v + m·g·v·sin(θ), where ρ air density, Cd·A drag area, Crr rolling resistance, m mass, v speed, θ slope. Complements cycling-speed and cycling-distance.
Formula
P ≈ 0.5·ρ·CdA·v³ + Crr·m·g·v + m·g·v·grade/100.
speed from power solves the same equation for v.
How to Use
- Enter speed, grade and rider weight (or a known power).
- The tool returns estimated power (or speed).
Case Studies
30 km/h, 0% grade, 80 kg
P ≈ drag + rolling ≈ 100–150 W on flat.
FAQ
Why does speed cubed appear?
Air drag power grows with the cube of speed, so aero matters most at high speed.
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.