Free tool
Estimate your FTP from a 20-minute or ramp test.
Estimate your cycling FTP from a 20-minute all-out or TrainerRoad-style ramp test. Plug in 20-minute average power or the final 1-minute peak from a ramp protocol and the calculator returns FTP, the full 7-zone Coggan power table, and recommended interval targets. Free, in-browser, no signup.
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FTP = average watts × 0.95 (Coggan)
Estimated FTP
238WCoggan power zones
| Zone | Name | Range |
|---|---|---|
| Z1 | Active Recovery | 0 - 131 W |
| Z2 | Endurance | 132 - 179 W |
| Z3 | Tempo | 181 - 214 W |
| Z4 | Threshold | 217 - 250 W |
| Z5 | VO2max | 252 - 286 W |
| Z6 | Anaerobic | 288 - 357 W |
| Z7 | Neuromuscular | 358+ W |
How it works
- 1
Pick a test protocol
A 20-minute time trial gives you a longer steady-state effort. A ramp test escalates wattage until failure. Either produces a single number that the calculator turns into an FTP estimate.
- 2
Execute the test fresh
Two easy days before. Standard warm-up. Same trainer, same bike, same setup as last time. If you change variables, you get noise, not data.
- 3
Enter the number
20-minute average power for the time-trial test. Best full minute for the ramp. The calculator multiplies by 0.95 or 0.75 respectively.
- 4
Read your zones
All seven Coggan zones are rendered as watt ranges. Lock them into your head unit or training app and ride to them, not to RPE alone.
The math
FTP is defined as the power you can hold for approximately one hour. Sustaining a one-hour all-out effort is impractical to do repeatedly, so two short proxies are used:
Worked example: 20-minute test at 280 W
If you average 280 W for a clean 20-minute effort, FTP = 280 × 0.95 = 266 W. At 70 kg body weight, that is 3.80 W/kg - solid Cat 4 territory on the Coggan tables.
Worked example: ramp test peak of 360 W
If your last full minute on a 20-watt-per-minute ramp averaged 360 W, FTP = 360 × 0.75 = 270 W. Same 70 kg rider gets 3.86 W/kg - within noise of the 20-min number, which is the point.
Where the zones come from
The standard seven-zone Coggan model is anchored at FTP and uses fixed percentages: Z1 ≤55%, Z2 56-75%, Z3 76-90%, Z4 91-105%, Z5 106-120%, Z6 121-150%, Z7 above 150%. The zones are population averages; individual physiology varies.
How to use this in training
FTP is the anchor for everything power-based. Once you have it:
- Build aerobic base in Z2. 70-80% of weekly volume should sit between 56% and 75% of FTP. This is where mitochondria and capillary density grow. Hours, not watts, are what matter here.
- Push threshold with Z4 intervals. 2×20 minutes at 91-105% of FTP is the canonical workout. Two sessions a week, sandwiched around recovery days, will move your FTP within 4-6 weeks.
- Stress VO2 with Z5 work. 5×4 minutes at 106-120% with 4-min recovery. Brutal but unavoidable if you want to raise the ceiling that FTP sits under.
- Use NP and IF, not just average watts. Variable rides need Normalized Power and Intensity Factor to compare honestly. See the TSS calculator for the math.
- Retest before you change zone targets. If sweet-spot 88% feels too easy, it might be time to retest - not to ignore the number.
Common mistakes & misconceptions
Testing tired
A test done at the end of a heavy block under-reads FTP by 5-15 watts. The number you live by should come from a rested state, otherwise every zone target is too easy.
Pacing the 20-min test wrong
Most riders start too hot and fade. The right pace is the highest sustainable wattage you can hold all 20 minutes - start conservative, build through the middle, empty the last 3 minutes.
Comparing trainer FTP to outdoor FTP
Indoor and outdoor power numbers diverge for almost every rider. Pick one as the reference for a block and use the other as supporting data.
Skipping the body weight input
Raw watts is meaningful on the flat. On a 6% climb, W/kg is the only ratio that determines who reaches the top first. If you race hills, log your weight every week.
Treating FTP as identity
FTP is one of many fitness markers. A higher anaerobic capacity, better fueling, sharper bike handling - all of these win races that pure FTP does not.
Using uncalibrated power
Zero-offset your power meter before every test. A 2% calibration drift moves your FTP by 5-7 watts at most power outputs - and every zone target moves with it.
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Open the toolkitFAQ
What is FTP in cycling?
Functional Threshold Power is the highest steady-state power you can sustain for approximately one hour. It anchors every power-based training zone and is the most widely used fitness benchmark in cycling.
Which is more accurate - 20-minute test or ramp test?
The 20-minute test is closer to a true one-hour effort and tends to give a slightly higher FTP than the ramp. The ramp is easier to repeat and less mentally brutal, so most athletes get more usable data from it over time. Pick the one you will actually do every 6-8 weeks.
How often should I retest FTP?
Every 4-6 weeks during a structured training block, or any time your perceived effort at threshold work shifts noticeably. Out of season or in heavy fatigue, retesting will under-read - wait until you are fresh.
Why does Coggan multiply by 0.95?
A 20-minute all-out effort is sustainable by most trained athletes for slightly longer than 20 minutes but not a full hour. Empirically, multiplying the 20-min average by 0.95 lands close to a one-hour sustainable power for most riders. It is a heuristic, not a law.
Why does the ramp test use 0.75?
In a ramp protocol you ride until failure. The last full minute before you can't hold the wattage is your peak minute. Roughly 75% of that one-minute peak is what you can hold for an hour. The 0.75 factor is calibrated against lab-tested cohorts.
Do I need a power meter to estimate FTP?
You need a calibrated power source: a dedicated power meter on the bike, or a smart trainer in ERG/level mode that reports power. Heart rate alone cannot estimate FTP because the heart-rate-to-power relationship is highly individual.
How does FTP differ from MAP or CP?
Maximal Aerobic Power (MAP) is the wattage at which VO2max is reached - it's about 1.15-1.20× your FTP. Critical Power (CP) is the asymptote of the power-duration curve and is often within a few percent of FTP but derived from multi-effort testing.
Is W/kg more important than raw FTP?
It depends on the terrain. On flat time-trial courses, raw watts dominate. On climbs, watts per kilogram is the right metric. Sprinters care about 5-second W/kg. Domestiques in 4-hour group rides care about endurance W/kg.
Why is my outdoor FTP lower than my trainer FTP?
Outdoor cycling adds wind, drafting variability, distractions, terrain, and traffic. Most riders measure 5-10% lower FTP outside. Train indoors for repeatability; train outdoors for the specificity your goal events demand.
Can my zones be wrong even if my FTP is right?
Yes - Coggan zones are a population average. Some athletes are diesel engines with a strong sweet spot but weak VO2; others are punchy with elite VO2 but a soft threshold. Use the zones as a starting frame and adjust based on what you can actually sustain.
Save your training to a real log
Every test, every zone, every block - tracked in one place. Domestique reads your FTP history and adjusts workouts as your fitness changes.
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