How to use it
- Choose FTP if you know your FTP, or 20-minute test if you have the average power of a 20-minute test.
- Type the power in watts under FTP or Average power of the 20-minute test.
- Type your Body weight and choose kg or lb under Weight unit.
- Read Watts per kilogram, then the zone table to see the watt range of each zone for your FTP.
How watts per kilogram is calculated
Watts per kilogram (W/kg) is the power you produce divided by your weight. It lets riders of different weights be compared: a 60 kg rider making 240 W and an 80 kg rider making 320 W both produce 4.0 W/kg.
FTP is functional threshold power. Training zones are set as percentages of it. If you have no FTP, a 20-minute test is used: BikeRadar gives the standard practice as 95 per cent of the 20-minute power, and credits Dr Andrew Coggan with the FTP standard.
W/kg = FTP ÷ body weight in kg
FTP from a 20-minute test = 0.95 × average power of the 20-minute test
1 lb = 0.45359237 kg- The result is an estimate: a power meter, the test conditions and the day all change the figure.
- The bike and the equipment are not part of the weight.
The seven power zones
Coggan's seven power zones are set as percentages of FTP. The page shows each zone as a percentage range and converts it to watts for your FTP. The top zone has no upper limit.
- Zone 1, active recovery: 0 to 55% of FTP.
- Zone 2, endurance: 56 to 75%.
- Zone 3, tempo: 76 to 90%.
- Zone 4, lactate threshold: 91 to 105%.
- Zone 5, VO2max: 106 to 120%.
- Zone 6, anaerobic capacity: 121 to 150%.
- Zone 7, neuromuscular power: above 150%.
What this does not cover
- The 95% factor is a practice, not a measurement. BikeRadar reports that coach Tom Bell uses about 90% for punchy riders and about 95% for diesel engines, and 93% for riders in between.
- The test itself: pacing and conditions change the 20-minute average, and so the FTP.
- Other ways of setting FTP, such as an hour-long test or a lab test.
Worked example: a 300 W test at 70 kg
The average power of the 20-minute test is 300 W. FTP is 95% of that: 0.95 × 300 = 285 W.
Watts per kilogram: 285 ÷ 70 = 4.07 W/kg. The zone bounds for an FTP of 285 W are rounded to whole watts.
| Zone | Percent of FTP | Watts at 285 W FTP |
|---|---|---|
| Z1 Active recovery | 0–55% | 0–157 W |
| Z2 Endurance | 56–75% | 160–214 W |
| Z3 Tempo | 76–90% | 217–257 W |
| Z4 Lactate threshold | 91–105% | 259–299 W |
| Z5 VO2max | 106–120% | 302–342 W |
| Z6 Anaerobic capacity | 121–150% | 345–428 W |
| Z7 Neuromuscular power | 151% and above | 430 W and above |
Frequently asked questions
What is FTP?
FTP, functional threshold power, is the power that training zones are set from. You can type a value you know, or estimate it from a 20-minute test, which is the common way to measure it at home.
Why is FTP 95% of the 20-minute test?
The 20-minute effort is the field test that most riders use to estimate FTP. BikeRadar gives the standard practice as 95 per cent of its average power, and notes that coaches adjust the factor for each rider.
Is a high watts per kilogram figure always better?
The figure compares riders of different weights, so it is most useful when you track your own value over time, on the same kind of test and the same scale.
Can I use pounds instead of kilograms?
Yes. Choose lb under Weight unit and the page converts your weight with 1 lb = 0.45359237 kg before it divides.
Why does the top zone have no upper limit?
The zone model gives Zone 7 as neuromuscular power above 150% of FTP, and it does not set an upper limit, so the page shows the zone from its lower bound upwards.
Does the page keep the numbers I type?
No. The calculation runs in your browser, and the page does not store or send what you enter.
Sources
- BikeRadar: what is FTP and why it matters for cyclists (the 95% practice, the 90% and 95% adjustments, the zone table)
- TRI-ALLIANCE: FTP power zones (seven zones as percentages of FTP, attributed to Coggan)
- TrainingPeaks: power training levels (zones relative to threshold power)
Figures and text last checked on Tuesday, November 10, 2026.