FTP and Cycling Power Zones Calculator
Estimate FTP from a 20-minute, 8-minute or ramp test, get all seven Coggan training zones in watts, and see your watts per kilogram.
| Zone | Watts | % of FTP | What it is for |
|---|
Before you train to these
- The boundaries are conventions, not cliffs. Riding at 90% of FTP does not become a different kind of exercise at 91%. The zones exist to give a shared vocabulary and to stop every session becoming moderately hard.
- The test factors are averages. A rider with a big anaerobic kick tests high on a 20-minute effort and will find the resulting zones brutal; a diesel tests low and will find them easy. Adjust from how the sessions actually feel.
- FTP drifts. It moves with training, fatigue, heat and altitude, and a figure from three months ago is a guess about today.
- W/kg describes threshold power on a bike and nothing else. It is not a measure of athleticism and certainly not of a person.
How to use
- Pick the test you did, or enter an FTP you already know.
- Enter the average power for that effort.
- Add your body weight for watts per kilogram.
- Read the zones, and treat the boundaries as conventions rather than cliffs.
Frequently asked questions
What is FTP?
Functional threshold power — roughly the power you could hold for an hour. Almost nobody tests it that way, because an hour flat out is miserable and the result measures tolerance as much as fitness, so it is estimated from a shorter effort and scaled down.
Why is a 20-minute test multiplied by 0.95?
Because a 20-minute effort includes an anaerobic contribution that cannot be sustained for an hour, and 5 per cent is the average size of that gap across many riders. It is an average, which means it is wrong for somebody: a rider with a large anaerobic kick tests high and will find the resulting zones brutal, and a steady diesel tests low and will find them easy.
What are the seven zones actually for?
Giving a shared vocabulary and stopping every session becoming moderately hard, which is the commonest way to train a great deal and improve slowly. Most hours belong in zone 2, a small number in zones 4 and 5, and the boundaries are conventions on a continuum — riding at 90 per cent of FTP does not become a different kind of exercise at 91.
Are these zones the same as heart rate zones?
No, and mapping one onto the other causes real confusion. Power is what you produce and responds instantly; heart rate is how your body is coping and lags by a minute or more, drifting upward through a long ride at constant power. They are complementary measurements, not two scales for the same thing.
What does watts per kilogram tell me?
How you will go uphill, mostly. On a climb, gravity dominates and the power you can produce per kilogram you have to lift is close to the whole story — which is why it is the number cyclists quote about climbing and a poor predictor of who wins a flat sprint.
Why do the bands differ for men and women?
Because the underlying distributions genuinely differ, and Coggan published them separately for that reason. Using one scale for everybody would misrepresent half the riders using it. Either way the bands are wide, and describe threshold power on a bike rather than athleticism.
How often should I retest?
Every six to eight weeks is a common rhythm, and more often is usually counterproductive — a test is a hard session that costs training time, and FTP does not move fast enough to justify chasing it. It also drifts with fatigue, heat and altitude, so a figure from a bad week is not a verdict.
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