Cycling Tool
Climbing Power Calculator
Estimate speed, VAM and climb time at target power with a road cycling power model.
Route and Equipment
km
%
W
kg
kg
km/h
Speed
17.9
km/h
Climb time
00:26:47
8.0 km
VAM
1075
m/h
Power Breakdown
| Source | Estimated power | Ratio |
|---|---|---|
| Grade gravity | 235 W | 84% |
| Aerodynamic drag | 25 W | 9% |
| Rolling resistance | 20 W | 7% |
Theory
Climbing power is mainly driven by the gravity term m g grade velocity. The steeper the road, the less CdA matters; as speed rises, aerodynamic drag grows quickly with the square of relative wind speed. Martin et al. (1998)'s road cycling model decomposes power into gravity, rolling resistance, aerodynamic drag and drivetrain loss, making it useful for pre-race climb estimates — which is also why losing weight pays off more on steep climbs while aero gear pays off more on gentle grades.
VAM reference values: VAM (vertical ascent rate, m/h) is a common way to compare climbing intensity: recreational riders sustain roughly 800-1000 m/h on long climbs; well-trained riders can reach 1200-1500 m/h; pros on key mountain stages can hit 1700-1800+ m/h (usually riders with low body weight and high power-to-weight). Comparing your own VAM on the same climb across different days reflects real climbing fitness better than speed alone.
Sources: Martin et al. 1998, J Appl Biomech