FTP zones calculator
Same formula as the Overload app
This FTP calculator finds your functional threshold power, either from a value you already know or from your best 20-minute average power, and splits it into the seven training zones used for structured cycling workouts. Enter your FTP directly, or your 20-minute best, and read off the exact watt range for recovery rides, endurance, tempo, threshold, VO2max, anaerobic and neuromuscular efforts.
FTP
250W
Power zones
| Zone | Range (W) |
|---|---|
| Active recovery | 0 – 138 |
| Endurance | 140 – 188 |
| Tempo | 190 – 225 |
| Threshold | 228 – 263 |
| VO2max | 265 – 300 |
| Anaerobic capacity | 303 – 375 |
| Neuromuscular | 378 – ∞ |
How it works
FTP is the highest power you can sustain for about an hour. Rather than testing a full hour, most riders estimate it from a hard 20-minute effort using Allen and Coggan's 95% rule: FTP equals 0.95 times your best 20-minute average power (Allen & Coggan, Training and Racing with a Power Meter, 2010).
Once FTP is known, the same source defines seven zones as fixed percentage bands of FTP, from active recovery below 55% up to short neuromuscular efforts above 150%. Each zone targets a different physiological system, from fat-burning endurance to anaerobic capacity.
Training with zones set from a current FTP keeps intervals accurate as fitness changes, since every zone boundary moves automatically when FTP moves.
Frequently asked questions
How accurate is the 20-minute FTP test?
The 95% rule is a solid field estimate, typically within a few percent of a true hour-long test for most trained riders. It can overestimate FTP for riders who pace a 20-minute effort poorly or underestimate it for those with strong anaerobic capacity relative to their aerobic base.
How often should I retest my FTP?
Every 4 to 8 weeks during structured training is common, or whenever workouts feel consistently too easy or too hard for their target zone. Retesting after a training block, rather than mid-block, gives the cleanest comparison to your previous number.
What zone should most training happen in?
Most structured plans spend the bulk of weekly hours in zone 2, endurance, with smaller, focused blocks of tempo, threshold or VO2max work layered on top. The right mix depends on your goal race and how many hours you can train.
Related tools
- Watts per kg calculatorWork out your cycling power-to-weight ratio and rider category for free, using the Coggan power profile for men and women.
- Speed to power calculatorEstimate the power needed to hold a cycling speed, free, with gravity, rolling and aero components and a full speed table.
- Climb time calculatorPredict climb time, speed and VAM from length, elevation gain and power, free, with a table across a range of power outputs.
- Bike gear calculatorList every chainring and cassette combination sorted by development, free, with ratio, gear inches and speed at your cadence.
Overload tracks your FTP and time in zone automatically
Overload estimates FTP from your rides and shows exactly how much time you spend in each power zone. Free on iOS and Android.