FTP test and power zones: how to test, calculate and use them
Functional Threshold Power (FTP) is the practical benchmark most cyclists and triathletes use to set power zones. It is an estimate of the highest power you can hold for roughly an hour, not a lab measurement. This guide shows how to test it, how to read the result, and how to turn it into training zones.
Open the FTP & Cycling Power Zones CalculatorWhat FTP is, and what it is not
FTP is a field estimate of your sustainable threshold power. Different tests give different numbers because they stress different systems, so the most useful FTP is the one you measure the same way every time. Treat it as a reference for pacing and zones, not as a fitness score.
Option 1: the 20-minute test
This is the classic field test. Do it fresh, on the same bike or trainer you normally use, and keep conditions repeatable.
- Warm up for about 20 minutes, including a few short harder efforts.
- The full field-test protocol includes a 5-minute all-out effort followed by 10 minutes easy before the 20-minute test. If you omit it, label the test as a different protocol and do not assume the same 95% conversion is equally accurate. Validate the estimate in sustained training.
- Ride 20 minutes as hard as you can hold evenly. Start slightly below your limit and avoid a fast start you cannot hold.
- Estimate FTP as 95% of your 20-minute average power.
Example: a 263 W average over 20 minutes gives an estimated FTP of about 250 W (263 × 0.95 = 249.85 W).
Option 2: the ramp test
A ramp test raises the target power in small steps until you cannot continue. For example, TrainerRoad's ramp test estimates FTP as 75% of the best one-minute power within its test. Use the protocol and calculation specified by your platform; this factor is not universal. Compare results from the same protocol and validate the estimate in sustained training.
From FTP to seven power zones
Coggan's original levels use FTP percentages for aerobic training. Level 6 is above approximately 120% of FTP; level 7 describes short maximal sprints and has no fixed FTP percentage. These are training descriptions, not seven contiguous numerical intervals. The calculator uses a simplified numerical convention (over 120% up to 150%, and over 150%) for its last two zones; those cutoffs are not Coggan's original definitions.
| Level | Name | % of FTP |
|---|---|---|
| 1 | Active recovery | up to 55% |
| 2 | Endurance | 56 to 75% |
| 3 | Tempo | 76 to 90% |
| 4 | Threshold | 91 to 105% |
| 5 | VO2max | 106 to 120% |
| 6 | Anaerobic capacity | above approximately 120% |
| 7 | Neuromuscular power | N/A: short maximal efforts |
Sweet spot is not a separate zone. It is a reference range of 88 to 94% of FTP that overlaps the top of tempo and the bottom of threshold. For 250 W that is 220 to 235 W.
How to use the zones in triathlon training
- Most volume belongs in zone 2. It builds aerobic fitness with low fatigue.
- Use zone 3 and sweet spot for steady, specific blocks when the race is a half or full distance.
- Use zone 4 and zone 5 intervals sparingly. They are costly and you still need to run well off the bike.
- Divide FTP by body weight in kilograms to get W/kg. It helps on climbs, but on flat courses absolute watts and aerodynamics matter more.
When to retest
Retest every 4 to 8 weeks, or after a training block. Use the same protocol, the same time of day and a similar level of freshness. Changing the test method changes the number, even if your fitness did not change.
FAQ
Is FTP the same as my one-hour power?
Not exactly. FTP is an estimate of what you could hold for about an hour. Real one-hour power depends on pacing, motivation and conditions.
Can I use heart rate instead?
Heart rate is useful but lags behind effort and drifts with heat, sleep and caffeine. Power responds immediately, which is why it is used for zones.
Should I trust my watch's automatic FTP?
Treat it as a rough guide. A deliberate test, repeated with the same method, is easier to compare over time.