FTP Calculator
Calculate FTP metrics for training, nutrition, and performance planning.
This FTP calculator estimates Functional Threshold Power - the highest power a cyclist can sustain for about an hour - from a shorter 20-minute test effort, and breaks that FTP value into standard training zones.
Enter your average power from a 20-minute maximal effort, and the calculator returns your estimated FTP and training zones.
Worked Calculation Examples
| Scenario | Result | Calculation Step |
|---|---|---|
| 20-minute average power: 250W | FTP ≈ 237.5 W | FTP = 250 × 0.95 = 237.5 W. |
| 20-minute average power: 300W | FTP = 285 W | FTP = 300 × 0.95 = 285 W. |
The 20-Minute FTP Test Formula
FTP is commonly estimated as 95% of average power sustained during a maximal 20-minute effort: FTP = 20-minute average power x 0.95. This shorter, more practical test approximates the power a rider could sustain for a full hour, since a true one-hour maximal effort test is harder to perform reliably.
Using FTP to Set Training Zones
Once FTP is known, cycling training zones are typically defined as percentages of FTP - for example, roughly 56-75% for endurance, 76-90% for tempo, 91-105% around threshold, and above 105% for VO2 max and anaerobic efforts. These zones let a cyclist target specific physiological adaptations during structured training.
How to Use the FTP Calculator
- Open the FTP Calculator and enter the values requested in the input fields.
- Check the units, percentages, dates, or time periods before reading the answer.
- Review the instant result and adjust any value to compare another scenario.
- Use the formula, example, and FAQs below to understand how the ftp calculator works.
Frequently Asked Questions
How do you calculate FTP from a 20-minute test?
Multiply your average power output from a maximal 20-minute effort by 0.95 (95%) to estimate your one-hour Functional Threshold Power.
Why use a 20-minute test instead of a full hour?
A true one-hour maximal effort is physically demanding and hard to pace consistently, so the shorter, more practical 20-minute test with a 95% adjustment provides a reliable and less exhausting estimate of the same underlying fitness metric.
How do I use FTP to set training zones?
Multiply your FTP by standard zone percentage ranges (roughly 56-75% for endurance, up through 105%+ for VO2 max efforts) to find the specific wattage targets for each training zone.
How do I use this ftp calculator?
Enter the known values, review the units or settings, and the calculator updates the result instantly. The formula and example on this page show how the answer is produced.
What does the FTP Calculator calculate?
Calculate FTP metrics for training, nutrition, and performance planning. It is designed for fast browser-based calculations without sign-up, downloads, or manual spreadsheet setup.
What formula does this ftp use?
The formula is: FTP = 20-Minute Average Power × 0.95. The FTP concept and its associated training zone system were popularized by coaches Hunter Allen and Andrew Coggan in their influential 2006 book Training and Racing with a Power Meter, which established the 95% adjustment factor and seven-zone training model that remains the standard framework used by cycling coaching software and power meter platforms today.
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Last updated: September 27, 2026.