Power To Weight
Calculator

It's your sustained power output in watts divided by your body weight in kilograms, expressed as W/kg. It's the key predictor of climbing and sprinting performance in cycling because it determines how quickly you can move your body mass against gravity.

On a climb, gravity resistance scales with total weight, so a lighter rider needs less power to achieve the same speed uphill. This is why W/kg, not raw wattage, is the standard metric for comparing climbing ability across riders of different sizes.

Roughly 2-3 W/kg sustained for an hour is typical for a fit recreational cyclist, while elite professional climbers can sustain over 5.5-6 W/kg. These benchmarks are usually quoted for FTP, a nearly maximal effort sustainable for about an hour.

Losing weight can raise your ratio, but cutting too aggressively often reduces the power output itself, especially muscle-driven power, canceling out the benefit. Most gains come from building raw power through training while managing weight sensibly rather than through extreme cuts.

Less so; on flat ground, aerodynamic drag dominates and total power output matters more than weight, since air resistance doesn't care how heavy you are. Power-to-weight becomes most decisive as gradient increases.