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Climb Time Calculator
How long will a climb take? Pick a climb or enter your own, add your weight, your bike's weight and the power you can hold, and get an estimated time, speed and climbing rate. Example: a 72 kg rider on an 8 kg bike at 216 W (3 W/kg) needs about 1:14 for Alpe d'Huez by our model.
Estimate your time
Estimated time: 1:14:06
Steady power, no wind, no stops, and the average grade of the whole climb, so irregular climbs will be less accurate. Your values are saved only in this browser.
Example times for every climb on this site
Our model, a 72 kg rider on an 8 kg bike (80 kg in total), steady power, site defaults.
| Climb | Distance | Gain | 3 W/kg (216 W) | 2 W/kg (144 W) | 4 W/kg (288 W) |
|---|---|---|---|---|---|
| Alpe d'Huez | 13.8 km | 1,120 m | 1:14 | 1:49 | 57 min |
| Mont Ventoux | 21.8 km | 1,617 m | 1:49 | 2:39 | 1:24 |
| Col du Tourmalet | 19 km | 1,404 m | 1:34 | 2:18 | 1:13 |
| Col du Galibier | 18.1 km | 1,245 m | 1:25 | 2:04 | 1:06 |
| Télégraphe + Galibier | 34.8 km | ~2,100 m | 2:27 | 3:33 | 1:55 |
| Col de la Croix de Fer | 29 km | 1,506 m | 1:50 | 2:37 | 1:27 |
| Col du Glandon | 21.3 km | 1,472 m | 1:40 | 2:26 | 1:17 |
| Col de la Madeleine | 19.3 km | 1,520 m | 1:41 | 2:29 | 1:18 |
| Col du Ranfolly | 14.5 km | 870 m | 1:01 | 1:28 | 48 min |
| Col de Joux Plane | 11.6 km | 990 m | 1:05 | 1:36 | 50 min |
| Avoriaz | 13.6 km | 830 m | 58 min | 1:24 | 45 min |
| Chamrousse | 18.2 km | 1,324 m | 1:29 | 2:11 | 1:09 |
| Passo dello Stelvio | 24.3 km | 1,808 m | 2:01 | 2:58 | 1:33 |
| Monte Zoncolan | 10.1 km | ~1,200 m | 1:16 | 1:53 | 58 min |
| Passo di Gavia | 16.5 km | ~1,320 m | 1:28 | 2:09 | 1:07 |
| Alto de l'Angliru | 12.5 km | 1,266 m | 1:21 | 2:01 | 1:02 |
| Col d'Izoard | 15.9 km | 1,095 m | 1:15 | 1:49 | 58 min |
| Col d'Aubisque | 16.6 km | 1,190 m | 1:20 | 1:58 | 1:02 |
| Col de la Bonette | 23.2 km | ~1,590 m | 1:48 | 2:38 | 1:24 |
| Sa Calobra | 9.4 km | ~670 m | 45 min | 1:06 | 35 min |
How we calculate
Speed comes from a steady power balance on a constant grade: power × drivetrain efficiency = v × m × g × (sin θ + Crr × cos θ) + ½ × ρ × CdA × v³, where v is speed, m is rider + bike + kit, g = 9.80665 m/s², θ is the angle of the average grade, Crr is rolling resistance, ρ is air density and CdA is the drag area. We solve it for v, and time = distance ÷ v. No wind, no stops, steady power.
Our defaults are Crr 0.005, CdA 0.40 m², air density 1.15 kg/m³ and no drivetrain loss: the same assumptions as our gearing guide and the Angliru page, so the numbers on the site agree. You can change them under "Assumptions".
The model has the same structure as the road-cycling power model of Martin, Milliken, Cobb, McFadden and Coggan, "Validation of a mathematical model for road cycling power", Journal of Applied Biomechanics 14(3): 276–291 (1998). In that study, modelled and measured power agreed closely (R² = 0.97, standard error 2.7 W). Their test bike used Crr 0.0032 and a drivetrain efficiency of 97.698%, so their rider was faster than our more cautious defaults would predict. Leave efficiency at 1 to match the rest of this site.
Questions
How long does Alpe d'Huez take?
By our model, about 1:14 for a 72 kg rider on an 8 kg bike at 3 W/kg (216 W), about 1:49 at 2 W/kg and about 57 min at 4 W/kg. Real rides differ with wind, stops and how evenly you pace.
What power should I enter?
The power you can hold steadily for about an hour of climbing. If you have a power meter, use a recent long climb or a one-hour test. Without one, try a few values and compare the result with a climb you know.
Does bike weight matter?
Yes. Climbing speed depends on the total weight you lift (rider + bike + kit), so 1 kg off the bike counts the same as 1 kg off the rider for the time.
More tools: Power-to-weight calculator · Gear calculator