🚴 FTP Cycling Calculator
Enter your 20-minute test average power to estimate your Functional Threshold Power (FTP) and training power zones.
Ninety-five percent of your 20-minute power
The tool uses the Coggan 20-minute protocol: FTP is the average power you held for 20 minutes, cut by 5%. The seven zones are then percentage windows of that FTP.
FTP = 20-min average power × 0.95
Z1 Recovery 0-55% Z2 Endurance 56-75% Z3 Tempo 76-90%
Z4 Threshold 91-105% Z5 VO2 Max 106-120%
Z6 Anaerobic 121-150% Z7 Neuromuscular 151-300%A 263 W test gives 263 × 0.95 = 249.85 W, shown as 250 W. Zone 2 works out at 140-187 W and Zone 4 at 227-262 W. Ranges are built from the unrounded 249.85, so they can sit a watt off hand-multiplying the displayed 250.
Getting a test worth using
- Pace it flat. The 0.95 factor assumes an even, maximal 20 minutes. Start too hard, fade, and the average - and every zone below it - comes out low.
- Retest when the top zones stop hurting. An FTP eight weeks old prices your intervals wrong.
- Zone 7 is a formality. Its window reaches 300% of FTP - sprint territory measured in seconds, not a range you ride to.
Frequently asked questions
How do I calculate FTP from a 20 minute test?
Multiply your 20-minute average power by 0.95. A 263 W average gives an FTP of 250 W.
Why is FTP 95% of the 20 minute figure?
FTP is meant to approximate the power you could hold for about an hour, and almost everyone averages more over 20 minutes than over 60. The 5% cut is the standard allowance for that difference.
What are my zone 2 watts?
Zone 2 endurance runs from 56% to 75% of FTP. With a 250 W FTP that is 140 to 187 W.