Power to weight ratio calculator
On a climb, everything reduces to watts per kilogram. It is the single most predictive number in cycling.
W
%
Watts per kilogram
3.889
- Climbing speed
- 15.07
- Time for the climb
- 0:39:49
- VAM, vertical metres per hour
- 1206
- Elevation gained
- 800
- Watts per kilogram including the bike
- 3.457
Show the working
- Power = 280
- Rider mass = 72
- Bike and kit mass = 9
- Climb gradient = 8
- Climb length = 10
- Watts per kilogram = 280 / 72 = 3.888 89
- total_mass = 72 + 9 = 81
- climb_speed = 81 * g0 * 8/100 > 0 ? 280 * 0.95 / (81 * g0 * 8/100) : 0 = 4.185 87
- Climbing speed = 4.185 87 * 3.6 = 15.0691
- Time for the climb = 4.185 87 > 0 ? 10 * 1000 / 4.185 87 : 0 = 2388.99
- VAM, vertical metres per hour = 15.0691 * 8/100 * 1000 = 1205.53
- Elevation gained = 10 * 1000 * 8/100 = 800
- Watts per kilogram including the bike = 280 / 81 = 3.456 79
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
The formula
- climbing speed = power x efficiency / (total mass x g x gradient)
- VAM = climbing speed x gradient, in metres of ascent per hour
These bands are for a sustained hour effort, roughly functional threshold power.