Power to Weight Calculator
Use this power to weight calculator to calculate watts per kilogram (W/kg), a common measure of cycling performance. Power to weight is particularly important for climbing and endurance cycling performance.
Average Power
Power to weight ratio: --
Body Weight
What Is Power to Weight Ratio?
Power to weight ratio - expressed as watts per kilogram (W/kg) - is one of the most useful metrics in cycling and triathlon. It normalises power output against bodyweight, allowing meaningful comparisons between athletes of different sizes and allowing you to track your own improvement over time regardless of weight fluctuations.
How to Calculate It
You need two values: your functional threshold power (FTP) in watts, and your bodyweight in kilograms. FTP is the highest average power you can sustain for approximately 60 minutes. Divide your FTP by your bodyweight to get your W/kg.
What the Numbers Mean
For recreational cyclists and triathletes, a W/kg of 2.5 to 3.5 is typical. Well-trained amateur athletes often sit between 3.5 and 4.5 W/kg. Professional road cyclists competing at the highest level may exceed 6 W/kg. These ranges give context, but your own trajectory over time is more useful than comparing yourself to benchmarks.
In triathlon, power to weight is particularly relevant on hilly courses where climbing ability is a significant differentiator. On flat courses, absolute power and aerodynamics play a larger role.
Improving Your Power to Weight Ratio
There are two levers: increasing power output and reducing bodyweight. Structured cycling training - particularly threshold and sub-threshold work - is the most direct way to build FTP. Bodyweight changes should be approached carefully in the context of training load; reducing bodyweight while maintaining a significant training volume requires attention to fuelling and recovery.
Want to build FTP and cycling performance as part of a structured triathlon plan? Explore online coaching at stevebarbour.com.