ToolNest

Watts per Kg Calculator

Power-to-weight and FTP ratingRuns locally · nothing uploaded

Sex
Watts per kg
3.29 W/kg
FTP
230 W
FTP rating
Good
FTP W/kg ratings (male)
RatingW/kg
Untrained< 2.23
Fair2.23 – 2.78
Good2.79 – 3.92
Excellent3.93 – 5.04
Superior≥ 5.05
Estimated climbing speed
GradientSpeedVAM (m/h)
6%16.7 km/h999
8%12.8 km/h1,018
10%10.4 km/h1,031
12%8.7 km/h1,039
15%7.1 km/h1,047

Steady climb at FTP, no wind resistance, rolling resistance 0.005. Less accurate on shallow grades.

Also works as:w/kg calculatorpower to weight ratio cyclingftp ratingclimbing speed calculator

How it works

Formula

FTP = test power × factor (20 min 0.95, 8 min 0.90, ramp 0.75)
W/kg = FTP ÷ body weight
Climb: FTP = mass × 9.81 × v × (sinθ + 0.005cosθ)

No air resistance; VAM = v × sinθ × 3600.

Worked example

Given: FTP 230 W, 70 kg rider, 8 kg bike

  1. 230 ÷ 70 ≈ 3.29 W/kg (Good).
  2. On 8%: v ≈ 3.56 m/s ≈ 12.8 km/h, VAM ≈ 1018 m/h.

Result: 3.29 W/kg; about 12.8 km/h on an 8% climb.

Sources

  • Allen H, Coggan A. Training and Racing with a Power Meter. 2nd ed. 2010.

How to use

  1. 1Choose the power source, enter power and weight.
  2. 2Pick your sex to see the rating.
  3. 3Check estimated speed on different gradients.

FAQ

What is a good W/kg?

On Allen & Coggan's FTP scale, men 2.8–3.9 is good, 3.9–5.0 excellent and 5.05+ superior; women about 2.4–3.3, 3.3–4.3 and 4.3+.

Why multiply a 20-min test by 0.95?

FTP is roughly your best one-hour power; 20-minute power is typically about 5% higher.