Watts Per Kilogram Calculator
Predicts climbing. Predicts almost nothing on the flat.
Work out Watts Per Kilogram. Predicts climbing. Predicts almost nothing on the flat. Answers in the units the job actually uses.
Power to weight
3.47 W/kg
Category 3 / competent club rider · 13.7 km/h up a 8% gradient
Power to weight predicts climbing and very little else. On a gradient almost all the power goes into lifting mass against gravity, so the ratio is what decides who gets to the top first. On flat ground it predicts almost nothing, because there the fight is against the air and absolute watts win — which is why sprinters and climbers are built completely differently. The category bands are the ones cyclists use in conversation and they map loosely to racing categories, which vary by country and federation. Treat them as orientation rather than a licence. The climbing speed ignores air resistance, which is a fair approximation above about 6% where speeds are low. On shallower gradients it will overstate what you can actually hold.
How the Watts Per Kilogram Calculator works
Power-to-weight from FTP and body weight, with the category bands cyclists use and the speed it implies on a climb. On a gradient almost all the power goes into lifting mass, which is why this ratio decides climbing and very little else.
Also known as: is 4 watts per kg good · power to weight ratio cycling · what category am i cycling · how fast can i climb
Not medical advice. This calculator gives a general estimate, not medical advice. It cannot account for your individual health, medical history, or medication. Talk to a qualified healthcare professional before acting on any result.
Frequently asked questions
What is a good watts per kilogram?
Around 2.5 W/kg is a fit recreational rider, 3.0 to 3.7 a competent club rider, 4.0 puts you above most amateur racers, and World Tour professionals sustain 5.5 to 6.5 at threshold.
Why does power to weight matter on climbs?
Because on a gradient the work is almost entirely lifting mass against gravity, and speeds are low enough that air resistance barely registers. On the flat the fight is against the air, where absolute watts win regardless of weight.
Should I lose weight or gain power?
Whichever is further from your ceiling. Losing 3 kg and gaining 12 watts have the same effect on the ratio; the difference is that power gains are permanent and weight loss below a healthy level costs power. Most riders have more room in training than on the scales.
What is FTP?
Functional threshold power — roughly the highest power you can sustain for an hour. It is normally estimated from a 20-minute test taking about 95% of the average, since almost nobody wants to do the full hour twice a season.
Does bike weight count in the ratio?
Not in the ratio itself, which uses body weight by convention. It does count in climbing speed, which is why the calculator asks for it separately — it is total mass being lifted, not just yours.
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