VAM Calculator (Climbing Speed and Estimated W/kg)
Average climbing speed in vertical metres per hour, the gradient, and a rough estimate of the watts per kilogram that it takes.
Results
What this tool does
VAM — from the Italian for average ascent speed — is how many vertical metres you climb per hour, a figure that lets climbs of different steepness be compared. Elite riders are commonly quoted at around 1,500 m/h and more on long mountain climbs. Michele Ferrari's rule of thumb turns it into power: W/kg ≈ VAM ÷ (200 + 10 × gradient %). It is only an estimate: it ignores wind, drafting, rolling resistance and bike weight, and is least reliable on gentle slopes where air resistance matters more. Enter the length along the road and the height gained; stops should be left out of the time.
Formula
VAM = metres climbed ÷ hours · W/kg ≈ VAM ÷ (200 + 10 × gradient %) (Ferrari's rule of thumb)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
cl | Height climbed (vertical metres) | m |
ds | Length of the climb | km |
hr | Hours | h |
mi | Minutes | min |
bm | Rider's mass (to turn W/kg into watts) | kg |
VM | VAM (vertical metres per hour) | m/h |
GR | Gradient | % |
SP | Average speed on the climb | km/h |
WK | Estimated power per kilogram (rough) | W/kg |
WT | Estimated power of the rider (rough) | W |
Worked example
- Height climbed (vertical metres)800 m
- Length of the climb10 km
- Hours0 h
- Minutes55 min
- Rider's mass (to turn W/kg into watts)70 kg
- VAM (vertical metres per hour)873 m/h
- Gradient8.0 %
- Average speed on the climb10.9 km/h
- Estimated power per kilogram (rough)3.12 W/kg
- Estimated power of the rider (rough)218 W
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- This tool is informational only. It does not diagnose, treat or replace a qualified health professional. Speak to a doctor before making decisions about your health.