Cycling FTP Calculator

What Is FTP?

Functional Threshold Power (FTP) is the highest average power you can sustain for about an hour — the point where your body shifts from being able to hold a pace comfortably to accumulating fatigue that will force you to slow down. It's the standard reference number in structured cycling training, since nearly every workout intensity is prescribed as a percentage of FTP rather than a fixed wattage, letting a training plan scale to any rider's fitness level.

How to Use This Calculator

Perform a 20-minute all-out effort (ideally after a proper warm-up, ramping into it rather than starting flat out) and enter your average power for those 20 minutes. The calculator estimates your FTP and breaks it into the seven training zones used in most structured cycling plans.

How We Calculate It

FTP = 20-minute average power × 0.95. The 5% reduction accounts for the fact that a 20-minute maximal effort is paced slightly harder than a true one-hour threshold effort, based on the widely used protocol popularized by Andrew Coggan and Hunter Allen. Power zones are then calculated as percentages of that FTP, following Coggan's standard seven-zone training model.

A Few Notes

This field-test estimate is close enough for most training purposes, but it's still an estimate — true FTP is best confirmed with a real one-hour time trial or through consistent training data tracked over time, both of which account for pacing strategy and day-to-day form better than a single 20-minute test. FTP also isn't static: retest every 6-8 weeks or after a focused training block to keep your zones current as fitness changes.