FTP Calculator

FTP stands for Functional Threshold Power, the highest average power in watts you can hold for about an hour. It is the anchor for power-based training because most workout zones are set as a percentage of it. A higher FTP means you can ride harder for longer.

Ride a hard, steady 20-minute effort and record your average power. Multiply that average by 0.95 to estimate FTP. The 5% reduction accounts for the fact that you can hold slightly more power for 20 minutes than you can for a full hour.

The 20-minute test takes 95% of your 20-minute average power. The 8-minute test uses 90% of your best 8-minute average, since a shorter effort runs at a higher intensity. The ramp test takes 75% of your best 1-minute power (your maximal aerobic power) at the end of a progressive ramp to exhaustion.

Watts per kilogram (FTP divided by body weight in kilograms) lets you compare riders of different sizes. As a rough male guide, recreational riders sit around 2.5 to 3.5 W/kg, strong amateurs reach 3.5 to 4.5 W/kg, and professional road racers exceed 5.5 W/kg. Women's reference values run a little lower across each band.

The Coggan model splits training into seven zones set as a percentage of FTP: active recovery (up to 55%), endurance (56 to 75%), tempo (76 to 90%), lactate threshold (91 to 105%), VO2max (106 to 120%), anaerobic (121 to 150%), and neuromuscular (above 150%). This calculator converts each band into a watt range using your FTP.

Most coaches suggest retesting every four to six weeks, since FTP changes as your fitness improves or declines. Test when you are rested and fueled, on the same bike and trainer setup, so the numbers stay comparable. Recalculate your zones each time so your workouts track your current fitness.