The VAM formula
W/kg ≈ VAM ÷ (200 + 10 × gradient %) (Ferrari)
VAM — velocità ascensionale media, average ascent speed — was popularised by coach Michele Ferrari as a way to compare climbing performances regardless of the climb’s length (source). His rule of thumb turns VAM into power per kilogram: on a steeper climb, more of your effort goes into lifting rather than overcoming air and rolling resistance, so the same VAM needs a little less power.
VAM to watts per kg
| VAM | 5% climb | 7% | 9% | 11% |
|---|---|---|---|---|
| 600 m/h | 2.40 W/kg | 2.22 W/kg | 2.07 W/kg | 1.94 W/kg |
| 800 m/h | 3.20 W/kg | 2.96 W/kg | 2.76 W/kg | 2.58 W/kg |
| 1000 m/h | 4.00 W/kg | 3.70 W/kg | 3.45 W/kg | 3.23 W/kg |
| 1200 m/h | 4.80 W/kg | 4.44 W/kg | 4.14 W/kg | 3.87 W/kg |
| 1400 m/h | 5.60 W/kg | 5.19 W/kg | 4.83 W/kg | 4.52 W/kg |
| 1600 m/h | 6.40 W/kg | 5.93 W/kg | 5.52 W/kg | 5.16 W/kg |
| 1800 m/h | 7.20 W/kg | 6.67 W/kg | 6.21 W/kg | 5.81 W/kg |
What is a good VAM?
As a rough guide, recreational riders often climb at 600–1,000 m/h, strong amateurs at 1,000–1,300 m/h, and professionals on long climbs at about 1,500–1,800 m/h. VAM depends heavily on gradient: shallow climbs give lower VAM at the same power, because more of it goes into speed against the wind.
An estimate. Ferrari’s formula assumes typical conditions. Wind, drafting, road surface and the weight of the bike all change the true figure; the climbing power calculator models them directly.
Last reviewed: 2026-10-04 · Disclaimer