FTP Calculator

In cycling your FTP, or Functional Threshold Power, is the power that, when fresh, you can just maintain for one hour.  FTP is used as a measure of your aerobic fitness. Increase your FTP, and you will increase your fitness and your performance over a wide range of cycling distances.

It is mentally and physically very difficult to measure your FTP by going flat out for an hour. More usually it is estimated by doing your best for 20 minutes, or 8 minutes or a Ramp Test, and then applying a factor to the power achieved.

What is not often appreciated is that the plot of Power vs Time follows a similar mathematical curve for all cyclists. Your FTP is just one point on that curve. Increase your FTP and all the other points within the aerobic range (3 to 90 minutes) will also increase. Conversely if we were measuring our maximum 20 minute power, and that increased, then so would our FTP also increase. 

Using this curve, it is easy to estimate your FTP from any duration within your "aerobic" range, between about 3 minutes and 90 minutes. Outside these times different curves will apply for either your anaerobic or fat burning energy systems.

Your rider type
A number between 4 and 90
A number between 0 and 59