Free cycling calculator

FTP Calculator

Estimate your functional threshold power from a 20-minute test, then get every training zone in watts — ready to ride.

Enter the average power you held for a full 20-minute test.

Estimated FTP

247W

95% of your 20-minute power

Your training zones

Power ranges calculated from your estimated FTP.

Cycling power training zones based on your estimated FTP
Zone% of FTPPower range
Z1 RecoveryUnder 55%0–136 W
Z2 Endurance56–75%137–185 W
Z3 Tempo76–90%186–222 W
Z4 Threshold91–105%223–259 W
Z5 VO2 Max106–120%260–296 W
Z6 Anaerobic121–150%297–371 W
Z7 Neuromuscular150%+372 W+

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What is FTP?

FTP stands for functional threshold power — the highest average power, in watts, that you can sustain for roughly an hour. It is the single most useful number in structured cycling training because it anchors your power zones: once you know your FTP, every workout intensity can be expressed as a percentage of it.

FTP sits near the boundary between efforts you can hold for a long time and efforts that force you to stop within minutes. Train just below it and you can accumulate a lot of work; push above it and fatigue arrives quickly. That is why coaches build training around it rather than around raw top-end power.

How FTP is calculated

The most common field estimate comes from a 20-minute test. You ride a maximal, well-paced 20-minute effort, take the average power, and multiply by 0.95:

The formula

FTP = 20-minute average power × 0.95

The 5% reduction exists because you can hold more power for 20 minutes than for a full hour. Subtracting it converts your 20-minute number into a practical estimate of true one-hour power. Other protocols exist — ramp tests, 8-minute tests, and longer efforts — and they can produce slightly different numbers, so treat your result as a well-grounded estimate rather than a fixed truth.

How to perform a 20-minute FTP test

A clean test is mostly about pacing and freshness. A workable protocol:

  • Arrive rested. Test on fresh legs — ideally after an easy day or rest day, not on the back of a hard block.
  • Warm up properly. 15–20 minutes of easy riding with two or three short, sharp efforts to open up the legs.
  • Optionally clear the legs. Many protocols include a 5-minute hard effort followed by easy spinning before the main test, so your first minutes are not artificially fresh.
  • Ride the 20 minutes evenly. Settle into a hard but sustainable pace you could just hold to the end. Resist going out too hard — fading badly in the last five minutes is the most common way to ruin the result.
  • Take the average and multiply by 0.95. Enter that 20-minute average in the calculator above to get your FTP and zones.

What is a good FTP?

To see where your number lands — from beginner to elite — compare it on the FTP benchmarks page. But raw FTP in watts is only half the story, because a heavier rider naturally produces more watts. For comparing riders, what matters is power-to-weight — watts per kilogram — which you can work out with the W/kg calculator and check against the W/kg chart. A 250 W FTP means something very different for a 60 kg climber than for a 90 kg rider.

More useful than chasing an absolute number is watching your own FTP trend over months of consistent training. For most amateurs, steady improvement and good fatigue management matter far more than hitting any particular benchmark.

FTP benchmarks

As a rough orientation by power-to-weight (FTP in W/kg), amateur men tend to fall around:

  • Beginner: under 2.0 W/kg
  • Recreational: 2.0–2.9 W/kg
  • Intermediate: 3.0–3.9 W/kg
  • Advanced: 4.0–4.9 W/kg
  • Competitive: 5.0–5.9 W/kg
  • Elite: 6.0+ W/kg

These are approximate, vary with sex, age, and testing method, and run lower for women at each level. For a fuller breakdown by rider type and absolute watts, see the FTP benchmarks page. Once you have your FTP, the cycling power zone calculator turns it into a full set of training zones with the purpose of each.

Frequently asked questions

How is FTP calculated from a 20-minute test?
FTP is estimated as 95% of your average power over a maximal 20-minute effort. The 5% reduction accounts for the fact that you can hold slightly more power for 20 minutes than you could sustain for a full hour, which is what FTP represents.
Why is FTP 95% of 20-minute power?
FTP approximates the highest power you could hold for about an hour. Most riders can sustain a bit more than that for 20 minutes, so subtracting 5% from a well-paced 20-minute test gives a practical estimate of true one-hour power without needing to ride all-out for a full hour.
How often should I retest my FTP?
Every 4 to 8 weeks is typical during consistent training, or after a notable block of work. Testing too often adds fatigue without new information; testing too rarely means your zones drift out of date as your fitness changes.
Is a 20-minute test accurate?
It is a good practical estimate for most riders when paced well, but it depends on pacing and freshness. Going out too hard inflates early power and tanks the back half; starting too conservatively underestimates your FTP. A ramp test or a longer effort can give a different number, so treat any single test as an estimate, not an absolute.
Do I need a power meter to use this FTP calculator?
You need a power source for the 20-minute average — either a power meter or a smart trainer that reports watts. Heart-rate-only estimates are far less reliable for FTP, because power is the metric FTP is defined in.

Train to your FTP, automatically

SmarterTraining builds each session around your current FTP and recovery, then runs it on your smart trainer over Bluetooth. Download the app and get a workout that fits the day in front of you.