The cycling power zone calculator above takes a single number — functional threshold power, or FTP — and divides it into the seven training levels published by Dr Andrew Coggan. Each level is defined as a percentage band of FTP, so once FTP is known the whole table is arithmetic. The calculator returns each band in watts, and in watts per kilogram if you supply a rider weight.
Arb Digital publishes this alongside a deliberately different tool. Our cycling power calculator answers a physics question: how many watts does it take to move a given rider and bike at a given speed on a given gradient. This page answers an entirely separate question: given a rider's own threshold power, where do the published intensity bands fall. One works forward from speed and slope to watts; the other works outward from one measured wattage to a table of ranges. They share a unit and nothing else.
What This Cycling Power Zone Calculator Does
It applies the published percentage bands to your FTP and reports the watt range for each of the seven levels. It will also derive FTP for you from a 20-minute test using the conventional 95 per cent factor, and it converts every band into watts per kilogram so the same table can be read in relative terms.
What it does not do is prescribe anything. It does not tell you how long to spend in any level, how many sessions to do, or which band suits a goal. Those are coaching decisions that depend on training history, available hours, recovery, health and what the rider is actually preparing for, and no percentage table has access to any of that. The calculator reports how a published system divides a number.
It is also distinct from heart-rate work. Our heart rate zone calculator divides a heart rate range into percentage bands, and the max heart rate calculator feeds it with an age-prediction formula. Heart rate and power are different signals with different behaviour: power responds instantly and heart rate lags, drifts with heat and dehydration, and varies day to day at identical workload. The two sets of zones are not interchangeable and do not line up cleanly on any given ride.
How to Use It
- Choose how you are supplying FTP. Either enter a figure you already have, or enter the mean power from a maximal 20-minute effort and let the calculator apply the published factor.
- Enter the wattage. Use average power for the effort, not normalised or weighted power, and not a peak figure.
- Add rider weight if you want relative figures. Weight is optional and only affects the watts-per-kilogram column.
- Read the four headline bands in the grid, and the full seven-level breakdown in the bars underneath.
- Re-run it whenever FTP changes. Every band moves with FTP, so a table built on a stale figure is wrong at every level at once.
The Formula and the Published Bands
Each level is a percentage range of FTP. According to TrainingPeaks' published description of Coggan's power training levels, the seven levels are: Level 1 active recovery below 55 per cent of FTP; Level 2 endurance at 56 to 75 per cent; Level 3 tempo at 76 to 90 per cent; Level 4 lactate threshold at 91 to 105 per cent; Level 5 VO₂max at 106 to 120 per cent; Level 6 anaerobic capacity above 121 per cent; and Level 7 neuromuscular power, which is not defined as a percentage at all.
That last point is worth pausing on. Level 7 covers very short maximal efforts where the limiting factor is neuromuscular rather than metabolic, and where power figures are so far above threshold that expressing them as a percentage of FTP stops being informative. The calculator therefore shows Level 7 as an open band above Level 6 rather than inventing an upper bound the source does not give. If a calculator hands you a tidy numeric ceiling for Level 7, it made it up.
Where the 95 Per Cent Factor Comes From
FTP is defined conceptually as the highest power a rider can hold in a quasi-steady state for approximately an hour. Testing that directly means riding flat out for an hour, which is unpleasant enough that almost nobody does it. The standard workaround is a 20-minute maximal effort with the result multiplied by 0.95.
This convention is documented in the research literature as well as in coaching practice. A study in Sports examining the validity of functional threshold power for cycling performance in moderately trained cyclists describes FTP as “the highest power a cyclist can maintain in a quasi-steady state without fatiguing for approximately 1 h” and states that the FTP figures used were 95 per cent of mean power in a 20-minute time trial, following Allen and Coggan's recommendation.
The factor is a convention, not a constant of nature. Riders differ in how their 20-minute power relates to their hour power — a rider with a large anaerobic contribution will over-shoot on a 20-minute test relative to their true hour power, and a diesel-type rider will under-shoot. That variation is one of the reasons two riders with the same 20-minute number can experience the resulting zones very differently.
Why the Zone Boundaries Are Not Physiological Walls
The bands are a labelling convention laid over a continuous physiological response. Nothing changes abruptly when a rider crosses from 90 to 91 per cent of FTP. The boundary exists so that efforts can be described and compared, not because the body switches mode at that wattage.
This matters most at the top of Level 3 and the bottom of Level 4, where the bands are narrow and the labels carry the most freight in training conversations. A rider whose FTP is slightly overstated will spend rides labelled as Level 3 that sit metabolically where Level 4 would be, and a rider whose FTP is understated has the opposite problem. The zone table is only ever as good as the FTP it was built from, and FTP itself is an estimate that moves with fitness, fatigue, heat, altitude and how the test was executed.
Watts, Watts Per Kilogram, and Which One Matters
Absolute watts determine speed on flat ground, where the dominant resistance is aerodynamic drag and the rider's weight barely enters the equation. Watts per kilogram determines speed uphill, where the dominant resistance is gravity and weight is most of the problem. This is why a heavy, powerful rider can dominate a flat time trial and lose contact on the first steep climb, and why a light rider with a modest absolute FTP can climb far faster than their flat-road speed suggests.
The calculator shows both because the same zone table reads differently through each lens. A rider comparing their Level 4 band to somebody else's should be clear which of the two figures they are comparing, and on what terrain the comparison is supposed to mean anything. For the flat-road physics side of that question, the cycling power calculator is the tool that models it directly, and the cycling pace calculator handles the speed, distance and time arithmetic that sits alongside it.
Reading a Power File Without Fooling Yourself
Two habits cause most of the confusion when riders apply a zone table to their own files. The first is comparing average power for a ride against a zone band. Average power over a variable ride can sit in Level 2 while the ride contained substantial time in Level 5 — the average of a hard interval session and the recovery between intervals is not a description of either. Time-in-zone distributions exist precisely because the average hides the shape.
The second is using a normalised or weighted power figure where an average belongs. Those metrics are built to reflect the physiological cost of a variable ride and are deliberately higher than the plain average for anything with surges in it. Feeding one into a test that expects average power inflates FTP, which then inflates every band in the table by the same proportion. If your zones feel harder than they should, check which power figure the FTP came from before concluding anything about form.
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Browse All Free Tools Talk to Arb DigitalCommon Mistakes to Avoid
- Building zones on a stale FTP. Every band is a percentage of one number, so an out-of-date FTP shifts the entire table at once.
- Feeding normalised power into a 20-minute test. The convention expects average power; anything weighted inflates FTP and therefore inflates every zone.
- Treating power zones and heart-rate zones as the same thing. Power is instantaneous and heart rate lags and drifts, so they will not agree within a ride.
- Judging a ride by its average power. An average can land in a band the ride never actually spent time in.
- Inventing an upper bound for Level 7. The published system does not define one, because percentages of FTP stop being meaningful at neuromuscular intensities.
Related Free Tools From Arb Digital
For the physics of watts against speed and gradient, use the cycling power calculator. For speed, time and distance arithmetic, the cycling pace calculator. For energy expenditure, the cycling calorie calculator; for gearing, the bike gear ratio calculator. On the heart-rate side see the heart rate zone calculator and the max heart rate calculator, and for oxygen uptake estimation the VO2 max calculator. Everything else is in the free online tools hub.
Frequently Asked Questions
As published by TrainingPeaks, they are Level 1 active recovery below 55 per cent of FTP, Level 2 endurance at 56 to 75 per cent, Level 3 tempo at 76 to 90 per cent, Level 4 lactate threshold at 91 to 105 per cent, Level 5 VO2max at 106 to 120 per cent, Level 6 anaerobic capacity above 121 per cent, and Level 7 neuromuscular power, which is not defined as a percentage.
Multiply your average power for a maximal 20-minute effort by 0.95. This is the published convention rather than a physical constant, and it fits some riders better than others depending on how much of their 20-minute power comes from anaerobic contribution.
No. A cycling power calculator estimates the watts needed to ride at a given speed on a given gradient, working forward from physics. This tool takes a rider's own threshold power and divides it into published percentage bands. They share the unit and nothing else.
Not reliably. Power changes the instant the pedalling effort changes, while heart rate lags behind it and also drifts upward over a long ride with heat and dehydration. The two sets of bands describe the same ride through different signals and will not align within it.
Because the published system does not define one. Level 7 covers very short maximal efforts limited by neuromuscular factors, at intensities where expressing power as a percentage of an hour-long threshold stops carrying useful information.
Absolute watts govern flat ground, where aerodynamic drag dominates and rider weight barely matters. Watts per kilogram govern climbing, where gravity dominates. The calculator shows both so a comparison can be made in whichever is relevant to the terrain in question.
There is no single answer, and it is a coaching question rather than an arithmetic one. What is certain is that the zone table is a fixed set of percentages, so it is only as current as the FTP behind it, and every band moves together when that number changes.
This tool reproduces a published percentage table for general information only. It is not a training plan, it prescribes nothing, and decisions about training intensity or volume belong with a qualified coach. Anyone with a health condition or symptoms should speak to their own physician before starting or changing hard exercise.
