Watts per Kg Calculator
Find your cycling power-to-weight ratio.
Results update as you type.
How it works
In cycling, raw power matters, but power relative to body weight matters more, and this calculator finds your power-to-weight ratio in watts per kilogram (W/kg). You enter your power output in watts — often your FTP (functional threshold power) — and your body weight in kilograms, and it returns your W/kg. The ratio is simply power divided by weight, and it is one of the best predictors of cycling performance, especially on climbs where riders must lift their own body mass against gravity. A lighter rider producing the same watts as a heavier one climbs faster, which is why professional climbers are lean and why W/kg, not just watts, is used to compare cyclists. Rough benchmarks for FTP W/kg: recreational riders are often around 2 to 3, strong amateurs 3 to 4, and elite and professional cyclists exceed 5, with the best reaching 6 or more at threshold. You can improve your ratio by increasing power through training or by reducing excess body weight — both raise W/kg. For time trials on flat ground, absolute power and aerodynamics matter more than W/kg, but for climbing and overall fitness comparison, W/kg is the key metric. Enter your power and weight to find your power-to-weight ratio.
W/kg = power (watts) ÷ body weight (kg)
Power-to-weight ratio is your power output in watts divided by your body weight in kilograms. It measures how much power you produce relative to your size, which largely determines cycling performance, especially when climbing, since every rider must move their own weight.
Source:Cycling performance
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter power output and body weight.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Power-to-weight updates instantly as you type — no button to press.
Frequently asked questions
What is a good watts per kg for cycling?
It depends on level. At functional threshold power, recreational riders are often around 2 to 3 W/kg, fit amateurs 3 to 4, competitive racers 4 to 5, and elite or professional cyclists above 5, with the very best exceeding 6. Context matters, but higher W/kg generally means better climbing and endurance performance.
Why does power-to-weight matter more than raw power?
Because cyclists must move their own body weight, especially uphill against gravity. A heavier rider needs more watts to climb at the same speed as a lighter one. Power-to-weight normalizes for size, so it predicts climbing and overall performance better than raw watts. That is why it is the standard way to compare cyclists of different builds.
What is FTP?
FTP, or functional threshold power, is the highest average power you can sustain for about an hour, a key benchmark of cycling fitness. W/kg is often expressed at FTP to compare sustainable performance. You can estimate FTP from a 20-minute test (taking about 95 percent of that average) and divide by your weight for your threshold power-to-weight ratio.
How can I improve my watts per kg?
You can raise the ratio two ways: increase your power through structured training that builds your threshold and aerobic capacity, or reduce excess body weight so the same power moves less mass. Both raise W/kg, and combining sensible training with reaching a healthy racing weight is how cyclists improve climbing performance most effectively.
Does watts per kg matter on flat ground?
Less so. On flat time trials and sprints, absolute power and aerodynamics dominate, because you are overcoming air resistance rather than gravity, and a bigger, more powerful rider can go faster despite a lower W/kg. Power-to-weight is most decisive on climbs and for overall endurance comparison, while flat performance favors raw watts and aero efficiency.