Free cycling calculator
W/kg Calculator
Turn your FTP and body weight into watts per kilogram — the power-to-weight ratio cyclists use to compare fitness — and see where you land.
Power-to-weight
3.33W/kg
Approximately intermediate level
Performance categories
Rough, widely used FTP-based guides. They vary with sex, age, and testing protocol, and women's bands typically run a little lower for the same level.
| Category | W/kg |
|---|---|
| Beginner | Under 2.0 |
| Recreational | 2.0–2.9 |
| IntermediateYou | 3.0–3.9 |
| Advanced | 4.0–4.9 |
| Competitive | 5.0–5.9 |
| Elite | 6.0+ |
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 W/kg 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.
What is a good W/kg?
There is no universal "good" number, but the rough bands below give orientation. They are widely cited FTP-based guides for amateur men; women's bands typically run a little lower for the same level, and all of them shift with age and testing protocol.
W/kg benchmarks
- Beginner: under 2.0 W/kg — new to structured training.
- Recreational: 2.0–2.9 W/kg — rides regularly for fitness.
- Intermediate: 3.0–3.9 W/kg — trains consistently; competitive on club rides.
- Advanced: 4.0–4.9 W/kg — strong amateur racer.
- Competitive: 5.0–5.9 W/kg — high amateur or regional elite.
- Elite: 6.0+ W/kg — domestic-elite to professional.
The calculator above highlights which band your result falls into. Treat it as a checkpoint, not a verdict. For the full picture by rider category and goal, see the W/kg chart, and compare your raw power on the FTP benchmarks page.
How to improve W/kg
There are only two levers, and one is usually better than the other:
- Raise FTP (the durable lever). Consistent training — endurance volume, plus threshold and sensible Zone 2 work — increases the watts on top of the ratio. This is the sustainable path for most riders.
- Reduce excess weight (carefully). For some riders there is healthy weight to lose, which raises the ratio without touching power. But aggressive dieting can sap power and harm recovery, so it should be gradual and, if you are unsure, guided by a professional.
For most amateurs, building power through structured, recoverable training is the lever that lasts. Once you know your FTP, map it to your training zones to see where that work should happen.
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.
- What is a good W/kg for cycling?
- It depends on context, but as a rough guide for amateur men, under 2 W/kg is beginner, 3–4 W/kg is a solid intermediate-to-advanced range, and 5+ W/kg is competitive. Women’s bands run a little lower for the same level. Most riders are better served tracking their own trend than chasing a number.
- 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 W/kg 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.
FTP Benchmarks
See how your FTP compares to typical rider categories, from beginner to elite.
W/kg Chart
Compare your watts-per-kilogram power-to-weight ratio against common rider levels.