Use our calculator to determine your W'
You must do these 2-things
- Ride as hard as you can for approximately 3-minutes, keep going if you can go longer than 3
- Find an 8 to 20-minute max effort
- Alternatively, you can put your FTP in the second box and enter 40 minutes.
Then just plug those values into our calculator
Critical Power and W' Calculator
* This came from the GoldenCheetah Sweatpy project. We use the 2-parameter non-linear method.
You can always hop on your trainer, do a solid warm-up and go as hard as you can for these efforts, try to pace yourself so it is even power and see what your average power is. You can repeat this a few times over a couple weeks to get your maximum value. With practice, your pacing will be better and your W’ will get more accurate.