Power-to-Weight Ratio Calculator
Calculate power per kilogram of body weight (W/kg) — widely used in cycling to compare performance independent of body weight.
How to use the power-to-weight ratio calculator
- Enter your power output in watts (e.g. threshold power/FTP from a cycling test).
- Enter your body weight in kilograms.
- Watts per kilogram and a rough performance level update automatically.
Why does power-to-weight matter?
Watts per kilogram (W/kg) expresses how much power you can produce relative to your own body weight. This matters especially in uphill cycling, where a lighter rider producing the same absolute power (watts) as a heavier rider will perform better — since it's the ratio between power and weight that determines how fast you climb, not absolute power alone.
Frequently asked questions
What is threshold power (FTP)?
FTP (Functional Threshold Power) is the highest power you can theoretically sustain for about one hour. This is the number usually used to calculate watts per kilogram for training purposes.
Why is power-to-weight more important than raw watts uphill?
Going uphill, you have to lift your entire body weight against gravity. A rider who weighs less needs less power to achieve the same climbing speed as a heavier rider — so the ratio between power and weight matters more than absolute power alone when the terrain rises.
Is a higher power-to-weight ratio always better?
For climbing and acceleration, yes — but on flat ground and in windy conditions, absolute power and aerodynamics also play a bigger role, so power-to-weight isn't the only metric that matters for performance.