What is VAM in cycling?
VAM — velocità ascensionale media, mean ascent velocity — is vertical meters climbed per hour, and it's climbing's cleanest speedometer: gain divided by time, nothing else. Climb 1,100 meters in 40 minutes and your VAM is 1,650 m/h, whatever the road did to get there. It became the pro peloton's favorite comparison number because it needs no power meter — a TV graphic, a stopwatch and a route profile are enough to estimate what a rider is producing.
How do you calculate VAM?
VAM = elevation gain in meters ÷ time in hours. Working in feet adds one step: divide by 3.28084 first. A 3,600 ft climb in 40 minutes is 1,097 m in 0.67 h, so 1,646 m/h (or, if you prefer your climbing in feet, about 5,400 ft/h). Use the gain from the segment, not the summit altitude minus the start — a climb with a dip in it makes you climb the dip twice, and the segment gain counts both. The calculator above takes either unit and does the conversion.
What's a good VAM?
| Rider | Typical VAM on a long climb |
|---|---|
| New to climbing | 400–700 m/h |
| Recreational, steady | 700–1,000 m/h |
| Trained amateur on a 45-min col | 900–1,200 m/h |
| Strong racer | 1,300–1,600 m/h |
| Grand Tour climbers, summit finish | 1,650–1,800+ m/h |
Approximate published ranges for sustained climbs of 30+ minutes; short steep efforts read higher. Anything over 1,000 is honest work.
VAM to watts per kilogram — shorthand vs physics
The peloton's rule of thumb, attributed to Dr. Michele Ferrari: W/kg ≈ VAM ÷ (200 + 10 × grade%). It's compact and roughly right — but it's a curve fit, so we also run the real thing: your VAM implies a road speed on that grade, and the same Martin power model behind our climb tools prices that speed exactly. For 1,644 m/h on 8.1% (a 65 kg rider), the shorthand says 5.85 W/kg; the physics says 6 — close enough to respect the folklore, precise enough to prefer the model. The calculator shows both for your climb.
VAM rewards steepness: on a gentle grade more of your power fights air instead of gravity, so fewer of your watts become altitude. The same 6 W/kg rider, computed by our engine: 5% → 1,362 m/h · 8% → 1,639 m/h · 12% → 1,777 m/h. That's why comparing VAMs is only fair on similar grades — and why the famous records were all set on steep mountains.
VAM on the famous climbs at 3, 4 and 5 W/kg
The same rider posts a different VAM on every mountain, because the grade decides how many watts turn into altitude. Here is what a 70 kg rider produces on the classics, computed by the physics engine:
| Climb | Grade · gain | 3 W/kg | 4 W/kg | 5 W/kg |
|---|---|---|---|---|
| Old La Honda (CA) | 7.3% · 393 m | 876 m/h | 1,140 m/h | 1,386 m/h |
| Box Hill (UK / Zwift) | 5% · 125 m | 808 m/h | 1,024 m/h | 1,214 m/h |
| Alpe d'Huez | 8.1% · 1,114 m | 889 m/h | 1,163 m/h | 1,421 m/h |
| Col du Tourmalet | 7.4% · 1,402 m | 878 m/h | 1,143 m/h | 1,391 m/h |
| Mont Ventoux (Bédoin) | 7.5% · 1,608 m | 880 m/h | 1,146 m/h | 1,396 m/h |
| Alto de l’Angliru | 9.8% · 1,209 m | 907 m/h | 1,195 m/h | 1,472 m/h |
70 kg rider + 8 kg bike, still air, on the hoods; published length and average grade per climb, gain derived from them. Times for the same table are on the climb time calculator.
Notice the spread down each column: at 4 W/kg the Angliru returns about 17% more VAM than Box Hill for the same legs. A VAM PR is a record on a road, not a physiological one, which is why the honest comparison across climbs is W/kg, not m/h.
What VAM do I need for a target time?
Turn the formula around: VAM needed = gain ÷ target hours. Alpe d'Huez gains about 1,114 m, so a one-hour ascent needs 1,114 m/h and a 75-minute one 891 m/h. Then the physics prices it: 1,114 m/h on 8.1% is about 3.82 W/kg for a 70 kg rider — which tells you whether the goal is a training block or a fantasy before you book the flight. Enter your own climb's gain and grade above with the time you want, and the W/kg lines give you the same answer.
Why VAM is not a power meter
VAM measures the road, not you. Four things move it without any change in your fitness: weight (a lighter rider at the same W/kg climbs at the same VAM, but at the same watts the lighter rider wins); drafting (a wheel to follow on a 5% grade is worth a meaningful slice of the aero cost, and the Ferrari shorthand assumes you're alone); wind, which the shorthand ignores entirely and the full model only handles if you tell it; and altitude, where thinner air makes a high pass slightly faster for the same watts. That's why the peloton uses VAM to estimate rivals' numbers from television and their own power meters to train — and why the calculator shows the physics-model W/kg beside the shorthand rather than pretending either is a measurement.
The VAM folklore ceiling is Marco Pantani's 1,791 m/h up Alpe d'Huez in 1997 — a number modern physiology regards with an eyebrow raised, given what that era's blood values looked like. Today's cleanest Grand Tour bests sit in the same neighborhood on their biggest days, which tells you how extraordinary sustained 1,800 really is. If your own col PR breaks 1,000, you've earned the coffee.
Using VAM to pace and to train
Without a power meter, VAM is your climbing power meter: pick a familiar climb, note the VAM at a sustainable effort, and repeat efforts against it — improvement in m/h at the same perceived effort is fitness, plain and undeniable. It also paces long ascents honestly: if the first ten minutes of a 1,100 m pass read 1,400 m/h and your best hour is 1,100, you're writing a check the summit will cash. Pair it with the W/kg calculator to see what the benchmark bands say about the number you're holding.