FTP and power zone calculator
FTP is the power you could hold for roughly an hour, and it anchors every structured session you ride with a power meter. Enter a 20-minute test (x0.95), an 8-minute test (x0.90), a full hour, or a ramp test, and this calculator returns your FTP, your W/kg and the full set of zones in either the seven-zone Coggan model or the three-zone polarized model.
An FTP taken from anything shorter than an hour is an approximation: the result moves with sleep, weather and motivation. Repeat the same protocol every 6 to 8 weeks so you are comparing like with like.
How is FTP calculated from each test?
By definition FTP is an hour of maximal steady effort, and almost nobody wants to ride that test. Cycling settled on shorter protocols instead, each with a published conversion factor:
FTP = 20 min power x 0.95 (Coggan / Allen protocol) FTP = 8 min power x 0.90 (Carmichael protocol) FTP = 60 min power x 1.00 (the definition itself) FTP = final full minute of a ramp x 0.75
Which one should you ride? The 20-minute test is the road standard if you can pace evenly. The 8-minute test forgives pacing mistakes, which makes it a good first attempt. A ramp test hurts least and repeats most reliably indoors, though strong sprinters tend to score high on it. The hour test is the gold standard and demands race-day motivation. Worked example: 230 W for 20 minutes gives an FTP of 219 W; at 187 lb (85 kg) that is 2.58 W/kg, a solid mid-pack amateur.
The 0.95 and 0.90 factors are population averages, and an individual can sit 2-3% either side of them. Treat the number as a starting point for training rather than a verdict. If the zones feel wrong in practice, with Z4 landing like Z5, adjust your FTP by a few watts and move on.
Coggan zones or polarized zones: what is the difference?
The Coggan model splits effort into seven zones expressed as a percentage of FTP, and it is what training apps display. The polarized model, built on Stephen Seiler's research, collapses the picture into three zones separated by two physiological thresholds and prescribes roughly 80% of riding time easy, 20% hard, with very little in the middle. Both describe the same physiology at different resolutions: Coggan names intervals precisely, polarization guards the shape of your whole week. This calculator switches between the two views with one tap.
Once you know your FTP, the climb time calculator turns it into minutes on a real gradient, and the cycling power calculator shows what those watts buy you in speed on the flat.
Frequently asked questions
- What is FTP in cycling?
- FTP, or Functional Threshold Power, is the highest power you can sustain for about an hour. It is the reference point for power-based training: every training zone is defined as a percentage of it. The concept was popularised by Andrew Coggan and Hunter Allen in Training and Racing with a Power Meter.
- How do you calculate FTP from a 20-minute test?
- Ride 20 minutes as hard as you can hold an even pace, then multiply your average power by 0.95. For example, 240 W for 20 minutes gives an FTP of roughly 228 W. The 0.95 factor corrects for the fact that 20 minutes is shorter than an hour, so the average comes out higher than true threshold.
- Ramp test or 20-minute test: which is better?
- A ramp test raises power every minute until you cannot continue. It is shorter, easier mentally and simple to repeat indoors, which is why it dominates winter training. The 20-minute test reflects real threshold endurance more closely but punishes bad pacing. Consistency matters more than the choice itself: only compare results from the same protocol.
- How often should you test FTP?
- Every 6 to 8 weeks, with the same protocol and comparable conditions: rested, same route or same trainer setup. Testing more often tells you little, because fitness does not move week to week, and the test itself is a hard session you have to recover from.
- What is a good FTP in W/kg for an amateur?
- As a rough scale: under 2.5 W/kg is recreational, 2.5-3.2 W/kg is a solid club rider, 3.2-4.0 W/kg is a strong amateur racing locally, and above 4 W/kg the competitive levels begin. WorldTour professionals sit at 5.5-6.5 W/kg. When comparing riders, W/kg says far more than raw watts, especially on climbs.