Free cycling calculator
W/kg Calculator: Convert FTP to Watts Per Kilogram
Enter your FTP and body weight in kilograms or pounds. You get your power-to-weight ratio, the level it falls into, and the guide for reaching the next one.
Power-to-weight
3.33W/kg
Experienced (3.0–3.5 W/kg)
Next step: how to reach 3.5 W/kg.
Performance categories
Coaching orientation bands on the same 0.5 W/kg scale used everywhere on this site — not population percentiles. They are referenced to trained male amateurs and shift with age and testing protocol. How we set these bands, and why there is no female table.
| Category | W/kg |
|---|---|
| Novice | Under 2.0 |
| Recreational | 2.0–2.5 |
| Intermediate | 2.5–3.0 |
| ExperiencedYou | 3.0–3.5 |
| Advanced | 3.5–4.0 |
| Competitive | 4.0–4.5 |
| Elite amateur | 4.5–5.0 |
| Elite | 5.0+ |
SmarterTraining automatically adjusts workouts as your fitness improves.
What is watts per kilogram?
Watts per kilogram (W/kg) is your power divided by your body weight. It expresses how much power you produce relative to how much mass you have to move, which is why it is the standard way cyclists compare fitness across different body sizes.
The formula
W/kg = FTP (watts) ÷ body weight (kg)
Most often W/kg is calculated from FTP, giving a threshold power-to-weight ratio that reflects sustained climbing and endurance fitness. You can also calculate it for shorter durations (5-minute or sprint W/kg), but the FTP-based figure is the one riders quote most.
Why watts per kilogram matters
Whenever you have to lift your own body against gravity — climbing a hill, accelerating, riding into a long drag — what determines your speed is power relative to weight, not raw watts. A 90 kg rider with a 300 W FTP (3.3 W/kg) and a 60 kg rider with a 200 W FTP (also 3.3 W/kg) will climb at a similar pace despite a 100 W gap, because the heavier rider has more mass to carry.
On the flat, where aerodynamics dominate, raw watts matter more. But for most amateur goals — climbing better, hanging onto the group on hills, comparing yourself to training benchmarks — W/kg is the more meaningful figure.
Converting FTP to W/kg
The conversion is one division, but two details trip people up:
- Pounds first. W/kg is defined in kilograms. If you weigh yourself in pounds, divide by
2.2046before dividing your FTP by it — the calculator's lbs toggle does this for you. - Use body weight, not system weight. Power-to-weight for cycling is quoted against your body mass alone. Bike weight matters on a real climb, but it is not part of the W/kg figure riders compare.
- Use a like-for-like FTP. A ramp-test FTP and a 20-minute-test FTP are not interchangeable, so a W/kg built on one is not comparable to a W/kg built on the other. See ramp test vs 20-minute test.
Working backwards is just as useful: to find the FTP you would need for a target ratio, multiply the target by your weight. A 78 kg rider aiming at 3.5 W/kg needs 78 × 3.5 = 273 W. The FTP-needed-at-every-body-weight table has that worked out for every common weight and target.
What your result means
The calculator above highlights which band your result falls into and links to the guide for reaching the next one. Treat it as a checkpoint, not a verdict — and for the interpretation rather than the arithmetic, these are the pages to read:
- Is 2.5, 3, 4, or 5 W/kg good? — what each number actually gets you on the road.
- The full W/kg chart — every band, plus the FTP each one needs at your body weight.
- W/kg by age — how the ranges shift across the decades.
- What counts as a good FTP — the raw-watts side of the same question.
- How to improve your W/kg — the two levers and a realistic timeline for each level.
Once you have your FTP, map it to your training zones so the work that raises the ratio lands where it should.
Frequently asked questions
- How do you calculate watts per kilogram?
- Divide your FTP in watts by your body weight in kilograms. For example, a 250 W FTP at 75 kg is 250 ÷ 75 = 3.3 W/kg. If your weight is in pounds, divide by 2.205 first to convert to kilograms.
- How do I convert my FTP to W/kg if I weigh myself in pounds?
- Divide your weight in pounds by 2.2046 to get kilograms, then divide your FTP by that. A 185 lb rider is 83.9 kg, so a 260 W FTP is 260 ÷ 83.9 = 3.1 W/kg. The calculator’s lbs toggle does the conversion for you.
- What is a good W/kg for cycling?
- As a coaching reference for trained male amateurs — not a population percentile — under 2.0 W/kg is novice, 2.5–3.0 is intermediate, 3.5–4.0 is advanced, and 4.0+ is the conventional gateway to competitive amateur racing. These are referenced to male riders and we do not publish a separate numeric table for women. See our "what is a good W/kg" guide for what each number actually gets you on the road.
- Why does W/kg matter more than raw watts?
- On any effort where you carry your own weight — climbing especially — what moves you is power relative to mass. A heavier rider produces more raw watts but not necessarily more speed uphill. W/kg lets riders of different sizes compare threshold fitness on equal terms.
- Should I use FTP or peak power for W/kg?
- For sustained performance and climbing, use FTP, since it reflects the power you can hold for a long time. Peak or sprint W/kg over a few seconds is a different metric used for sprinting and short, explosive efforts.
- Is losing weight or gaining power better for W/kg?
- Both raise the ratio, but they are not equal for everyone. Gaining power through training is generally the healthier, more sustainable lever for most amateurs. Aggressive weight loss can cost you power and compromise recovery and health, so it should be approached carefully and, if in doubt, with professional guidance.
Watch your watts per kilogram climb
SmarterTraining adjusts your workouts as your fitness improves, so the work stays effective as your numbers move. Download the app and train power-to-weight the sustainable way.
Related calculators & benchmarks
FTP Calculator
Estimate your FTP from a 20-minute test and get your seven cycling power zones in watts.
Cycling Power Zone Calculator
Generate a full training-zone table from your FTP — percentages, watt ranges, and what each zone trains.
What Is a Good FTP?
What counts as a good, average, or competitive FTP in watts — and why body weight changes the answer.
W/kg Chart
The full power-to-weight scale, plus the FTP you need for each W/kg target at every body weight.