Cycling Power-to-Weight Calculator
Work out your cycling watts per kilogram from FTP and body weight, and see where your W/kg lands on the rider-category scale.
How it works
Power-to-weight = FTP (W) ÷ body weight (kg)
On a sustained climb, gravity dominates and your speed tracks watts per kilogram far more than raw watts — a 60 kg rider at 240 W (4.0 W/kg) out-climbs an 85 kg rider at 300 W (3.5 W/kg). The category bands follow Andrew Coggan’s power profile: recreational riders cluster near 2.5–3.5 W/kg, and 5+ W/kg at threshold is professional territory. Sprint W/kg over 5 seconds tells a different story and can exceed 20 for track sprinters.
Worked example
FTP 250 W at 75 kg: 250 ÷ 75 = 3.33 W/kg — a solid Cat 3–4 club rider. Dropping to 72 kg at the same FTP lifts it to 3.47 W/kg.
Frequently asked questions
How do I find my FTP?
The common field test is a 20-minute all-out effort; take 95% of the average power as FTP. A ramp test or a genuine 60-minute best effort also work.
Why does W/kg matter more than watts on hills?
Climbing work is lifting your total mass against gravity, so per-kilogram power sets the pace. On the flat, aerodynamics and absolute watts matter more.
Is losing weight always the answer?
Only down to a healthy point. Cutting too far costs the muscle and glycogen that produce power, which lowers the numerator faster than the denominator.
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This calculator is for educational purposes. Double-check important results before acting on them.