Your power to weight ratio is an important indicator of your cycling performance, particularly your climbing abilities.
In this article, we’ll discuss power to weight ratio for cycling, why it matters, and how to measure your power-to-weight ratio on the bike.
We’ll be covering:
- What Is Power To Weight Ratio?
- How To Calculate Your Power To Weight Ratio
- Benefits Of Understanding Your Power To Weight Ratio
- What Is the Purpose of Power to Weight Ratio?
- What Is A Good Power to Weight Ratio for Cyclists?
- Power To Weight Ratio Charts By Sex
- How To Improve Your Power To Weight Ratio
Let’s dive in!
What Is Power To Weight Ratio?
Power to weight ratio refers to the power a cyclist can generate (in watts) per kilogram of body weight.
The unit used to describe power to weight ratio is W/kg.
While raw power is the primary indicator of potential speed and performance on flat land, the power-to-weight ratio metric is often used as an indicator of climbing performance, though it has other uses as well.
Bear in mind that your power to weight ratio will vary according to the time duration being measured. You’ll be able to sustain a higher power output for a ten-second sprint than for a thirty-minute climb!
How To Calculate Your Power To Weight Ratio
You don’t need a dedicated power to weight ratio calculator to do this: it’s a very simple formula.
Simply measure the Watts you can sustain for a set period of time with a power meter or smart trainer, and divide it by your weight in kilograms.
For example, if you weigh 70 kg and can sustain an average output of 250 Watts for 15 minutes, your power to weight ratio would be 3.57 W/kg for that duration.
Most cyclists are interested in calculating their power to weight ratio at specific physiological thresholds or during certain cycling power tests, such as the Functional Threshold Power (FTP) or Critical Power (CP).
Calculating your power to weight ratio at your maximal steady-state power or lactate threshold can also be really helpful to inform your training and compare your progress over time.
Additionally, if you have a bike with a high-tech power meter, you might be able to set the display to actually show your W/kg as you ride, so you don’t have to calculate it on your own.
The Benefits Of Understanding Your Power To Weight Ratio
One of the benefits of the power-to-rate ratio metric in cycling is that it allows cyclists of different body types and sizes to compare themselves on a more equal playing field.
A smaller, lighter rider might not be able to push as many watts on the bike as a larger cycling mate with more muscle mass.
However, when you compare the power to weight ratios between two different cyclists, you eliminate the differences in absolute body size and are comparing just the degrees of relative strength.
Some cyclists also like to track their power to rate ratio over specific climbs that they hit frequently on their training rides.
By monitoring your average power-to-weight ratio for the climb, you can monitor your improvements over time.
It’s also common to see cyclists testing their power-to-weight ratio on one-minute and five-minute all-out efforts.
A one-minute sprint can be a great indicator of your anaerobic capacity, while five minutes roughly represents your VO2 max or aerobic capacity.
What Is the Purpose of Power to Weight Ratio?
Your power to weight ratio on the bike is particularly important when you are climbing due to the fact that when you’re ascending a hill, gravity is the main source of resistance to your forward motion.
Therefore, a lighter cyclist with a higher power-to-watts ratio will get to the top of the hill faster than a rider pushing the same Watts but who weighs more, and therefore has a lower power to weight ratio.
In simple numbers, if two cyclists are producing 240 Watts up a hill, the cyclist who weighs 60 kg (4 W/kg) will get up the hill faster than the cyclist who weighs 80 kg (3 W/kg).
Additionally, if you’re a cyclist who has taken to the world of virtual cycling with platforms such as Zwift or Rouvy, your W/kg metric is used to determine how fast your virtual self rides, and is used by Zwift to seed you into a category for races and group rides.
Finally, measuring your power-to-weight ratio over different durations or at different physiological thresholds can give you an indication of where you are the weakest because you can compare your own W/kg for each stage of endurance.
What Is A Good Power to Weight Ratio for Cyclists?
With all this in mind, you’re probably asking yourself: What is a good power to weight ratio for cyclists?
Of course, it all depends on the distance or duration, as well as the level and sex of the cyclist.
Professional cyclists often have a power-to-weight on an FTP test upwards of 6 W/kg, which is outstanding. Decent amateurs might be closer to 3.5-4 W/kg on an FTP.
Dr. Andy Coggan put together a detailed power profile chart using maximal W/kg for men and women at different durations or thresholds and at different levels of cycling abilities.
Modified versions of Dr. Coggan’s results can be seen below.
You don’t need a power to weight ratio calculator – just use the simple formula listed above to work out your own power to weight ratio for comparison.
Power to Weight Ratio Chart for Men
|5 Sec (W/kg)||1 Min (W/kg)||5 Min (W/kg)||FTP (W/kg)|
Power to Weight Ratio Chart for Women
|5 Sec (W/kg)||1 Min (W/kg)||5 Min (W/kg)||FTP (W/kg)|
How To Improve Your Power To Weight Ratio
By definition, there are two factors in improving your power to weight ratio:
- Increasing your average power output.
- Reducing your weight.
Altering either of these, or both, will increase your W/kg on the bike.
Healthy weight loss entails consistently creating a moderate caloric deficit through diet and exercise.
Training to increase your raw power will depend on the duration that you are targeting.
For example, if you’re trying to increase your W/kg over one minute, you’ll want to engage in super high-intensity sprint training.
On the other hand, if you’re targeting W/kg over one hour, the focus will clearly be on endurance workouts.
To increase your W/kg at FTP or maximal steady-state power, a well-rounded training plan with base rides, intervals, threshold rides, and sprints is often the most effective, but it will depend on your relative strengths and weaknesses.