# What is my FTP?

Estimates cycling functional threshold power (FTP) as 95% of a 20-minute test, with watts per kilogram and the seven power training levels in watts.

- Page: https://www.acalculator.org/sports/ftp-calculator
- JSON spec: https://www.acalculator.org/sports/ftp-calculator.json
- Version: 23d33f88aa0a

## Default answer

Example with the default inputs (I have 20-minute test, 20-minute average power (W) 250, Weight in kg, Body weight (kg) 75): Your FTP is 237.5 W.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| m | I have | A 20-minute test result to estimate FTP from, or an FTP you already know. |
| p20 | 20-minute average power (W) | The average power of an all-out 20-minute effort, in watts. |
| ftp | FTP (W) | Your functional threshold power in watts. |
| u | Weight in | Kilograms or pounds for your body weight. |
| wt | Body weight (kg) | Your body weight in kilograms, for watts per kilogram. Leave it empty to skip. |
| wtlb | Body weight (lb) | Your body weight in pounds, for watts per kilogram. Leave it empty to skip. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| ftpW | FTP | Functional threshold power: 95% of the 20-minute power, or the FTP you typed. |
| wkg | Watts per kilogram | FTP ÷ body weight in kilograms. |
| z1 | Level 1: Active recovery | Active recovery: under 55% of FTP, in watts. |
| z2 | Level 2: Endurance | Endurance: 56% to 75% of FTP, in watts. |
| z3 | Level 3: Tempo | Tempo: 76% to 90% of FTP, in watts. |
| z4 | Level 4: Lactate threshold | Lactate threshold: 91% to 105% of FTP, in watts. |
| z5 | Level 5: VO2 max | VO2 max: 106% to 120% of FTP, in watts. |
| z6 | Level 6: Anaerobic capacity | Anaerobic capacity: 121% and above of FTP, in watts. |
| z7 | Level 7: Neuromuscular power | Neuromuscular power: no set percent of FTP, in watts. |

## Method

FTP = 0.95 × 20-minute average power; each level’s edges = FTP × its percent, rounded to whole watts.

## Assumptions

- The 20-minute test is an all-out, evenly paced effort after a warm-up; 95% of it estimates the power you could hold for about an hour.
- Levels follow the TrainingPeaks table as published, including its 1-point gaps (55% to 56%, 75% to 76% and so on).
- 1 lb = 0.45359237 kg exactly.

## Worked examples

1. m = test, p20 = 250, u = kg, wt = 75 gives ftpW = 237.5, wkg = 3.17, z1 = up to 131 W, z2 = 133–178 W, z3 = 181–214 W, z4 = 216–249 W, z5 = 252–285 W, z6 = 287 W and up. Source: TrainingPeaks Help Center, How to Calculate Threshold Values for Power, Heart Rate or Pace (FTP = 95% of the best 20-minute power), https://help.trainingpeaks.com/hc/en-us/articles/204071934-How-to-Calculate-Threshold-Values-for-Power-Heart-Rate-or-Pace; TrainingPeaks, Power Training Levels (levels 1 to 7 as % of threshold power), https://www.trainingpeaks.com/blog/power-training-levels/.
2. m = ftp, ftp = 200, u = lb, wtlb = 150 gives ftpW = 200, wkg = 2.94, z1 = up to 110 W, z4 = 182–210 W, z6 = 242 W and up. Source: NIST SP 811 (1 lb = 0.45359237 kg); TrainingPeaks, Power Training Levels (levels 1 to 7 as % of threshold power), https://www.trainingpeaks.com/blog/power-training-levels/.
3. m = test, p20 = 300, u = kg gives ftpW = 285, z2 = 160–214 W, z5 = 302–342 W. Source: TrainingPeaks, Power Training Levels (levels 1 to 7 as % of threshold power), https://www.trainingpeaks.com/blog/power-training-levels/.

## FAQ

### How do I calculate FTP from a 20-minute test?

Multiply the average power of the 20-minute effort by 0.95. A rider who averages 250 W for 20 minutes has an FTP of about 250 × 0.95 = 237.5 W. The 5% cut allows for the shorter effort, since FTP is the power you could hold for about an hour.

### What are the power zones?

The seven levels in the TrainingPeaks table are percents of FTP: active recovery under 55%, endurance 56–75%, tempo 76–90%, lactate threshold 91–105%, VO2 max 106–120%, anaerobic capacity above 121%, and neuromuscular power with no set percent (short sprints).

### Why are there gaps between the zones?

The published table lists whole percents: endurance ends at 75% and tempo starts at 76%. The calculator keeps those numbers as published, so a value between them, such as 75.5%, falls between two levels.

### What is a good watts per kilogram?

Watts per kilogram is FTP divided by body weight, and it matters most on climbs. It varies widely with age, sex and training, so compare it with your own past tests rather than a single target.

### How often should I retest my FTP?

Many coaches retest every 4 to 8 weeks of steady training, or after a break, so the zones keep matching your fitness. Test on the same bike and power meter each time.

## Sources

- TrainingPeaks Help Center, How to Calculate Threshold Values for Power, Heart Rate or Pace (multiply the best recent 20-minute power by 95%). https://help.trainingpeaks.com/hc/en-us/articles/204071934-How-to-Calculate-Threshold-Values-for-Power-Heart-Rate-or-Pace (retrieved 2026-10-19)
- TrainingPeaks, Power Training Levels (Coggan levels 1 to 7 as % of threshold power). https://www.trainingpeaks.com/blog/power-training-levels/ (retrieved 2026-10-19)
- NIST Special Publication 811 (2008), Appendix B.8: 1 lb = 0.45359237 kg exactly. https://www.nist.gov/pml/special-publication-811 (retrieved 2026-10-19)