How it works
W/kg = power (W) ÷ body weight (kg)
Power-to-weight ratio divides the power you produce by your mass. It matters because, on any climb, gravity is the main resistance, and the force needed to lift yourself plus the bike scales with weight — so two riders making the same watts but at different weights climb at different speeds. The lighter rider, or the one making more watts per kilo, goes faster uphill. To compare yourself against the Coggan power-profile chart, the duration of the effort matters: short maximal sprints produce very high W/kg (a track sprinter can exceed 20 W/kg for five seconds), while sustainable threshold power is much lower (elite road pros sit above 5.5 W/kg at threshold). Enter the duration that matches your power figure so the category is read off the right column. If you only know your watts in pounds-based units, switch the weight toggle to lb and the calculator converts to kilograms before dividing.
Sources
- Coggan power-profile chart Coggan, A. — power-profile tables giving W/kg category bands (untrained → world class) for 5-second, 1-minute, 5-minute and functional-threshold efforts.
- Why W/kg governs climbing On a gradient the dominant resistance is gravity acting on total mass, so climbing speed tracks power divided by weight (W/kg) far more closely than raw watts.
- Training and Racing with a Power Meter Allen, H. & Coggan, A. (2010). Training and Racing with a Power Meter (2nd ed.). VeloPress — origin of the power-profile framework.
FAQ
How do I calculate power-to-weight ratio?
Divide your power in watts by your body weight in kilograms. A rider holding 280 W who weighs 70 kg has a power-to-weight ratio of 280 ÷ 70 = 4.0 W/kg. Enter pounds and the calculator converts to kilograms for you.
What is a good W/kg for cycling?
At functional threshold (about an hour), recreational riders are around 2.5–3.0 W/kg, strong amateurs 3.5–4.0, and professional road racers above 5.5 W/kg. The thresholds are much higher for short sprints, which is why effort duration changes the category.
Why does the effort duration matter?
The Coggan chart has separate columns because sustainable power falls as effort lengthens. You can produce far more W/kg for 5 seconds than for an hour, so the same W/kg can be world-class over an hour but only average for a sprint. Choose the duration that matches your power number.
Should I lose weight or gain power to improve W/kg?
Either raises the ratio, but for most riders building sustainable power through training is safer and more durable than cutting weight. Aggressive weight loss can cost power and health — improve the ratio sensibly, not at any cost.
How does W/kg relate to FTP?
FTP in watts per kilogram is your threshold power-to-weight, the figure most often quoted for climbing ability. Calculate your FTP first, then divide by your weight — or just enter your FTP watts here with the threshold duration selected.
Does W/kg matter on flat ground?
Less so. On the flat, aerodynamic drag dominates and raw watts (and your aero position) matter more than weight. Power-to-weight is decisive on climbs and accelerations; absolute power rules on the flats.
The Coggan categories are population reference points, not a judgement of you, and depend on accurate power and weight measurement. Power meters vary; weigh yourself consistently. General training information, not medical, dietary or coaching advice — never pursue weight loss in a way that harms your health.