Climb Predictor

Road lines come from OpenStreetMap. Elevation comes from the USGS 3D Elevation Program for Pikes Peak, the IGN France 5 m model (RGE ALTI) for Alpe d'Huez, Mont Ventoux and the Tourmalet, the Copernicus EU-DEM (25 m) for the Stelvio, the IGN Spain 5 m model (MDT05) for Mallorca, the Geospatial Information Authority of Japan 5 m model for Mt Fuji, and the Copernicus GLO-30 (30 m) for Tai Mo Shan and Wuling. We sample the road every 5 m, smooth out tunnels and bridges, and split each climb into 25 m pieces. Pikes Peak runs from the Cascade toll gate to the summit; Sa Calobra from the port to the top near Coll dels Reis; Puig Major from Sóller to the tunnel; Coll de Sóller is the north side on the old Ma-11A road. Alpe d'Huez starts in Bourg-d'Oisans, Mont Ventoux in Bédoin, the Tourmalet in Luz-Saint-Sauveur and the Stelvio in Prato allo Stelvio. Tai Mo Shan starts in Tsuen Wan and follows Route Twisk to Tsuen Kam Au, then Tai Mo Shan Road to the top of the road. Mt Fuji runs up the Fuji Subaru Line from the toll gate to the 5th Station. Wuling follows the Taiwan KOM Challenge course from Qixingtan beach through Taroko Gorge to Wuling, about 103 km.

For each 25 m piece we solve the power balance: your power (less 2.5% drivetrain loss) against gravity, rolling resistance and air drag. Air gets thinner as you climb. We assume no wind, a steady effort on the hoods (CdA 0.32 m²), and no stops.

Less oxygen means less aerobic power. We use the hypobaric-chamber study by Wehrlin and Hallén (2006), which found endurance athletes lost about 6.3% of their VO2max for every 1,000 m (3,300 ft) above 300 m, and assume your climbing power falls by the same share. It matters a lot on Pikes Peak, which tops out above 14,000 ft, and very little in Mallorca.

Rolling resistance starts from BicycleRollingResistance.com drum tests (Continental GP5000 S TR, Terra Speed and Terra Trail) and is scaled up 34% for real asphalt, using SILCA's published drum vs new-asphalt measurements.

It is a physics estimate, not a guarantee. Wind, heat, fatigue, how well you have adapted to altitude, traffic and pacing will all move your real time. Most riders use it to plan pacing and check gearing before a trip, then compare it with their ride afterwards.

Yes. Under the FTP box, enter a local climb you have ridden hard: its distance, elevation gain and your time. We work out the average power that time takes for your weight and bike, then turn it into an FTP estimate. After a big climb, upload your ride file and we estimate your watts for every split the same way. Estimates from speed run high with a tailwind or drafting and low with a headwind or stops.

Yes, and you don't need to have ridden it. Pick "My climb" and upload a route you planned in Strava, Komoot or RideWithGPS, or a ride where you rode it. Google Maps routes won't work, because they carry no elevation. We take the biggest climb in the file, from its lowest point up to the top, smooth the elevation and split it into 25 m pieces, exactly as we do for our own climbs. Elevation comes from your file, so a route exported from a route planner or a ride recorded with a barometric altimeter works best. The prediction is free; the full plan, gear check and poster come with the All Climbs Pass.

It is read inside your browser. Nothing is uploaded to us or stored on a server. We use the GPS track, times, and power if your file has it, to find the climb and time each split.

No. It works out what your power, weight and equipment mean on a given road. It does not tell you how to train or what to eat.