Calculate VAM (vertical ascent per hour) from a climb you've already ridden — just elevation gain and climbing time.
This is measured VAM from a climb you've already ridden. To predict VAM from a power target before you ride, use the Hill Climb Calculator.
VAM (Velocità Ascensionale Media, Italian for "average ascent speed") measures how many vertical meters you climb per hour. It's a standard way to compare climbing performance across climbs of different lengths and shapes, widely used in professional cycling analysis to compare performances on entirely different mountains.
This calculator uses a completed climb's measured elevation gain and elapsed time — no power data or physics model needed:
Enter your elevation gain and climbing time above to calculate it directly from a ride you've already done.
Take a climb with 800 m of elevation gain, completed in 45 minutes:
Enter your own elevation gain and time above to calculate your VAM for any climb.
On a sustained climb, VAM and watts per kilogram track each other closely — higher W/kg produces higher VAM, all else equal. VAM has the advantage of not requiring a power meter, since it's derived purely from elevation and time; W/kg (a 4.12 W/kg example: 280 W over 150 lb) is the more precise number when you do have a power meter. See the W/kg Calculator to compute yours.
Climbing speed (km/h or mph) depends heavily on gradient — the same power produces a much slower ground speed on a steeper climb. VAM largely cancels that out, since a steeper climb covers more vertical meters per horizontal meter traveled. That's why VAM, not ground speed, is the standard way to compare climbing performance across climbs with different average gradients.
VAM is most reliable for sustained efforts longer than about 5 minutes on gradients roughly between 5-15%; very short, very steep, or very shallow climbs make VAM a less reliable point of comparison. Wind, road surface, drafting and pacing all affect the result too — VAM describes what happened on a specific climb, not a fixed physiological ceiling.
