Watts per Kg Cycling Category Calculator
Divide your cycling FTP by body weight to get watts per kilogram and the rider category it maps to.
How it works
W/kg = FTP ÷ body weight · category from threshold bands (female values shifted +0.75 W/kg to a common scale)
Functional threshold power divided by body weight is the single best predictor of climbing and sustained road performance, because on any gradient the rider is fighting their own mass. Categories map ranges of W/kg to rough racing tiers; the bands here follow Coggan-style FTP levels, with women's values shifted onto the same scale to reflect physiological differences. Two riders with identical FTP can sit in very different categories if their weights differ, which is why lightweight climbers punch above their raw wattage.
Worked example
A 250 W FTP at 75 kg is 250 ÷ 75 = 3.33 W/kg. For a man that falls in the 2.9–3.7 band — "Good (Cat 4)".
Frequently asked questions
What is FTP?
Functional threshold power is roughly the highest average power you can sustain for about an hour. It is usually estimated as 95% of a 20-minute maximal test.
Why divide by weight?
On climbs and accelerations you move your own mass, so watts per kilogram predicts performance far better than raw watts. On flat time trials, raw power and aerodynamics matter more.
Are these categories official?
They approximate widely used FTP tiers but are not a specific racing federation's licence categories, which vary by country and are based on results, not power alone.
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This calculator is for educational purposes. Double-check important results before acting on them.