Enter your best average power over 5 seconds, 1, 5, 20 and 60 minutes along with your weight. You will get your W/kg and your level at each duration, your rider type, your full power curve, your critical power and your training zones.
Leave blank anything you do not have. Two durations are enough to calculate everything else.
The bar runs from "untrained" to "world class" using the Coggan power profile categories for your reference table. A flat profile indicates a complete rider; the steps mark your strengths and weaknesses.
The horizontal axis is logarithmic: each equal step means multiplying the duration, which is how fatigue actually behaves. Hover or drag along the curve to read the power at any duration.
What you should be able to hold at each duration according to your critical power model. Rows marked measured are your own data; the rest are estimates.
| Duration | Watts | W/kg | % of FTP | Source |
|---|
The seven classic Coggan zones, calculated from your FTP.
| Zone | % FTP | Watts | W/kg | What it trains |
|---|
Indicative W/kg values for each category. Your position is highlighted in every column.
| Category | 5 s | 1 min | 5 min | FTP |
|---|
Categories from the power profile popularised by Andrew Coggan and Hunter Allen. They are indicative reference values: real racing level depends on far more than four numbers.
There is no need to measure a hundred different efforts. Four durations capture almost all the useful information, because each one interrogates a different energy system:
5 seconds measures neuromuscular power: raw force, fast-twitch recruitment and coordination. It is what decides a lead-out sprint.
1 minute measures anaerobic capacity: how much energy you can produce without oxygen before lactate stops you. It is the attack on a short climb or the final kilometre of an explosive finish.
5 minutes is the best field approximation of VO₂ max. It determines whether you hold the pace when the race splits on a short climb.
FTP (60 minutes) is your sustainable aerobic engine, the ceiling below which you can work for a long time. It rules time trials, long climbs and any ride over an hour.
What is interesting is not having a high 5 s, but having it high relative to your FTP. A profile with a high left side and a low right side describes a sprinter; the inverse pattern, a rouleur or a climber; a profile sagging in the middle with high extremes is rare, and almost always means specific VO₂ max work is missing.
That is why the meters on this page show your relative position at each duration and not just the watts: it is the only way to compare apples with oranges.
Your power curve is not just any line: above two minutes it fits a two-parameter model very well.
CP (critical power) is the asymptote: the power you could in theory hold indefinitely. In practice it sits very close to FTP, usually a little above. W′ ("W prime") is your reservoir of work above CP, measured in kilojoules: when you spend it, you stop. A large W′ lets you repeat attacks; a small one forces you to ride at a steady pace.
One practical consequence follows: if you know your CP and your W′, you know exactly how long you last at any power above threshold. At 50 W above your CP, with a W′ of 20 kJ, you have 400 seconds. Not one more.
| Duration | How to do it | Typical mistake |
|---|---|---|
| 5 s | Flying sprint from 30-35 km/h, out of the saddle, big gear | Starting from a standstill, which gives a lower peak |
| 1 min | Go hard but paced, squeeze the last third | Going flat out and dying at 40 s |
| 5 min | On a steady climb or a turbo, almost flat pacing | Starting too fast: it costs 15-20 W on average |
| 20 min | After 10-15 min of warm-up with a couple of openers | Doing it with fatigue from the day before |
| 60 min | A real time trial or a long flat-out ride | Never doing it and settling for the estimate |
The five tests are not done on the same day. Spread them out: the 20-minute and the 5-minute in separate sessions at least 48 hours apart, and the sprint always on fresh legs.
Because 20 minutes flat out is an effort you can partly ride above threshold, drawing on your anaerobic reserve. The 0.95 factor discounts that contribution. It is a reasonable approximation for most people, but not for everyone: a very explosive rider with a large W′ inflates their 20-minute test and should use a lower factor; a pure endurance rider can be close to 97 %. If you have entered your 60-minute power, the calculator uses it directly and ignores the estimate.
A single duration gives you very little. With two you can already fit critical power and draw a full curve. Four or five is ideal, and above all they should include a short effort (1 minute or less) and a long one (20 minutes or more): the model needs both ends so it does not invent the slope.
From the mean maximal power curve in your software: TrainingPeaks calls it Peak Power, Strava "Power analysis", Golden Cheetah "Critical Power". Take the best values from the last 6-8 weeks. Anything older no longer represents your current form.
No, and it depends on the terrain. Uphill W/kg rules, because you are fighting gravity and that depends on your mass. On the flat and in time trials absolute power rules, because air resistance depends on your frontal area, which grows far more slowly than weight. That is why climbers are light and rouleurs are big, and why a 60 kg rider at 4.5 W/kg climbs better than an 85 kg rider at 4.2 but loses on any flat road.
Every 6-10 weeks, or at the end of each training block. And always after a long rest period: keeping old zones is the most common way to train badly, whether by overshooting or undershooting.
Yes. Switch the reference table with the selector: the female categories have their own values, with bigger differences in the short efforts (where the muscle mass gap weighs more) than at threshold. The physics, the critical power model and the zones are identical.
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