Power zones calculator
Enter your FTP and see your six training zones in watts.
| Zone | Power | % of FTP |
|---|---|---|
| Z1recovery | up to 137 Wup to 55% | up to 55% |
| Z2endurance | 138–187 W56–75% | 56–75% |
| Z3tempo | 188–225 W76–90% | 76–90% |
| Z4threshold | 226–262 W91–105% | 91–105% |
| Z5VO2 max | 263–300 W106–120% | 106–120% |
| Z6anaerobic | 301 W and upabove 120% | above 120% |
Watt4 keeps these numbers up to date from every ride and plans your week around them. Free. Try Watt4
How power zones work
Power zones split your riding into ranges, each set as a share of your FTP. Because they are relative, the same zone means the same effort for a rider with a 180 W FTP and one with 320 W.
These are the zones the Watt4 app uses. They follow Andrew Coggan's classic model, with the two highest zones combined into one: zone 6 covers everything above 120% of FTP.
Getting the most out of them
Most riders spend too much time in zone 3: hard enough to tire you, not hard enough to raise your ceiling. A simple week keeps easy rides truly easy, in zones 1 and 2, and puts the hard work into a few focused interval sessions in zones 4 and 5.
Zones are only as good as the FTP behind them. If yours is a guess, start with the FTP calculator.
What each zone is for
- Z1 recovery
- Easy spinning for recovery rides and warm-ups. It should feel like almost nothing.
- Z2 endurance
- The base of your training. Long rides you could hold for hours while chatting.
- Z3 tempo
- Steady and purposeful. Sustainable for an hour or more, but you are working.
- Z4 threshold
- Around your FTP. Intervals of 8 to 20 minutes that raise the power you can sustain.
- Z5 VO2 max
- Hard efforts of 3 to 8 minutes that raise your aerobic ceiling.
- Z6 anaerobic
- Short, very hard efforts under two minutes, and sprints.
Questions
Why six zones, not seven?
The classic model has a seventh zone for sprints. Above about 120% of FTP, efforts are short enough that the exact number matters less than going hard, so Watt4 treats it as one zone.
What is the difference between zone 2 and zone 3?
Zone 2 (56–75% of FTP) is endurance: you can ride it for hours and still talk. Zone 3 (76–90%) is tempo: steady and sustainable, but you are working and conversation gets short.
Should I use power zones or heart-rate zones?
Power, if you have a power meter or smart trainer: it responds instantly and does not drift with heat or fatigue. Heart rate is a good second, and useful alongside power to see what an effort cost you.
Do my zones change?
Yes, whenever your FTP does. Work them out again after each test.