What Is Power-to-Weight in Cycling?
Power-to-weight ratio — watts per kilogram of body weight — is the number cyclists use to compare climbing ability, because gravity doesn't care about raw power, only power relative to the mass being hauled uphill. Two riders with the same 250-watt threshold climb very differently if one weighs 60 kg and the other 90.
Why w/kg predicts climbing
On a climb, most of your effort fights gravity, which scales with weight. So a lighter rider with the same watts, or an equal rider with more watts, climbs faster. Dividing your functional threshold power (FTP) by your weight in kilograms gives the ratio; the calculator converts pounds for you and places it on a rough scale from novice to elite.
Context matters
Power-to-weight rules the hills but not the whole sport. On flat roads and in sprints, raw watts and aerodynamics dominate, and a powerful heavier rider can crush a light climber. The most useful comparison is against your own past numbers: track your w/kg at FTP over a season to see fitness trends, rather than fixating on where you rank against others.
Frequently asked questions
- What is a good power-to-weight ratio?
- Recreational riders often sit around 2-3 w/kg; trained cyclists 3-4; elites above 5 at threshold.
- How do I calculate w/kg?
- Divide your FTP in watts by your body weight in kilograms.
- Does power-to-weight matter on flats?
- Less so — raw watts and aerodynamics matter more on flat terrain; w/kg dominates on climbs.