The Best Free Power Zone Calculator (and How to Use It)
A power zone calculator turns one number, your FTP (functional threshold power), into the full set of watts ranges you actually train in. Enter your FTP and ours lays out all seven Coggan power zones instantly, in watts, with what each one trains and how it should feel. It's free, it works on your phone, and it never asks for an email or an account. If you already know your FTP, you're about 10 seconds from your zones. The rest of this page explains how to use it, what to do if you don't know your FTP yet, and why we think it's the best free power zone calculator (sometimes searched as "powerzone calculator") on the web.
What a power zone calculator actually does
Training with power means training in zones, and every zone is just a slice of your FTP. Zone 2 endurance is 56–75% of FTP, threshold is 91–105%, and so on up to all-out sprints. Doing that maths by hand for seven zones, every time your fitness changes, is tedious and error-prone. The calculator does it the instant you type your FTP, and re-does it the moment you change the number.
We use the Coggan 7-zone model, the de facto standard that TrainingPeaks, Zwift, Garmin and Wahoo all build on, so the ranges you get here match what your head unit and training platform expect. We also mark your sweet spot (88–94% of FTP), the high-value band just below threshold that a lot of structured plans lean on. For the full explanation of what each zone develops, see our deep dive on the Coggan power zones.
How to use it (about 30 seconds)
- Enter your FTP in watts. If you know it from a recent test or your training platform, type it in.
- Read your zones. All seven bands appear immediately in watts, each labelled with what it trains and how it feels.
- Adjust and compare. Change the number and everything recalculates live, so you can see exactly how a 10-watt FTP gain shifts every zone.
FTP
250W
Sweet Spot
220–235W
88–94% FTP
| Zone | Range | What it trains |
|---|---|---|
| Z1 | Active Recovery ≤ 138 W | Recovery; spins the legs without adding load. RPE 1–2, very easy. |
| Z2 | Endurance 139–188 W | Aerobic base, fat oxidation, all-day pace. RPE 3–4, conversational. |
| Z3 | Tempo 189–225 W | Aerobic endurance and muscular efficiency. RPE 5–6, comfortably hard. |
| Z4 | Threshold 226–263 W | Lactate threshold, FTP work, the sustainable ceiling. RPE 7–8, 10–30 min reps. |
| Z5 | VO₂max 264–300 W | Maximal aerobic power; 3–8 min intervals. RPE 9, very hard. |
| Z6 | Anaerobic Capacity 301–375 W | Anaerobic capacity; 30s–3min efforts. RPE 9–10, near maximal. |
| Z7 | Neuromuscular Power ≥ 376 W | Sprint and neuromuscular power. RPE 10, all-out sprints. |
Z1 · Active Recovery. Recovery; spins the legs without adding load. RPE 1–2, very easy.
Z2 · Endurance. Aerobic base, fat oxidation, all-day pace. RPE 3–4, conversational.
Z3 · Tempo. Aerobic endurance and muscular efficiency. RPE 5–6, comfortably hard.
Z4 · Threshold. Lactate threshold, FTP work, the sustainable ceiling. RPE 7–8, 10–30 min reps.
Z5 · VO₂max. Maximal aerobic power; 3–8 min intervals. RPE 9, very hard.
Z6 · Anaerobic Capacity. Anaerobic capacity; 30s–3min efforts. RPE 9–10, near maximal.
Z7 · Neuromuscular Power. Sprint and neuromuscular power. RPE 10, all-out sprints.
- Andrew Coggan's seven-zone model expresses every zone as a percentage of Functional Threshold Power. Sweet Spot (220–235 W, 88–94% FTP) sits between Tempo and Threshold and gives a high training stimulus for moderate fatigue.
- FTP is the power you could theoretically hold for about an hour. Re-test every 4–6 weeks; a stale FTP makes every zone wrong.
A PDF of your personalized results, with a QR code to reopen them anytime.
That's the whole workflow. You can come back to the FTP calculator any time you retest and re-read your zones in seconds.
Don't know your FTP? Estimate it right here
You don't need a lab or even a separate test result. The same tool estimates FTP from a short maximal effort. Pick the test you did and it applies the standard factor:
- 20-minute test: FTP = 95% of your best 20-minute average power. The classic field test most training plans assume.
- 8-minute test: FTP = 90% of your best 8-minute power. Shorter and friendlier if a full 20 is daunting.
- Ramp test: FTP ≈ 75% of your 1-minute peak (MAP) at the end of a ramp. The least pacing-dependent option.
Do the effort honestly, drop the number in, and the calculator hands you both your FTP and your zones. For more on choosing and pacing a test, read what's a good FTP.
Why we think it's the best free power zone calculator
Plenty of sites will spit out a zone table. A few things set this one apart:
- More than one model. Most calculators only do Coggan FTP zones. If you'd rather anchor to a model that adapts the top end to your physiology, we also have Critical Power (which fits your CP and W′ from a couple of efforts) and Stryd-style running power zones. One site, the right model for your situation.
- Open, tested maths. Every formula on the site is implemented from its primary source and unit-tested against published reference values. See our methodology. No mystery numbers.
- Genuinely free, genuinely private. No email wall, no account, no upsell. Your FTP never leaves your device. There's no login because there's nothing to log into.
- Fast and mobile-first. It recalculates instantly and is built to use on a phone at the side of a turbo trainer, not just on a desktop.
We'd rather earn the "best free power zone calculator" label by being accurate, clean, and honest than by claiming it, so the reasons above are things you can check yourself.
Keep a record of your zones
Once you've got your zones, hit Download to save a clean PDF of your zone chart. It's print-identical to what you see on screen and carries a QR code that links straight back to the calculator, so you can:
- Pin it above your turbo trainer or tape it to your stem.
- Keep a dated record each time you retest, to see your FTP and zones climb over a season.
- Re-open the calculator from the QR code on your phone to recalculate after your next test.
There's no database and no account by design, so nothing is stored on our end. You keep the record, in a PDF that's yours. (Re-test every 4–8 weeks of focused training and save a fresh one; that dated stack of PDFs is a surprisingly motivating progress log.)
Power zones, heart-rate zones, or pace?
Power is the most precise tool for cyclists because it's what you actually produce: instant and unaffected by heat, sleep, or caffeine. Heart rate is how your body responds; it lags and drifts, which is why a 5-second sprint barely moves it. If you don't ride with a power meter, anchor your training to heart-rate zones or, for running, pace zones instead. Same easy-to-hard logic, different number. Many riders watch power for the effort and heart rate for fatigue, and that "mostly easy, a little very hard" shape is exactly what the polarized model prescribes.
Accuracy: garbage in, garbage out
The calculator is only as good as the FTP you feed it. A guessed or months-old FTP gives you confident but wrong zones, because every band shifts with it. So test honestly, retest every 4–8 weeks while you're training hard, and treat the boundaries as guidelines that overlap rather than hard walls (Coggan stresses this himself). Get the one number right and all seven zones fall out of it correctly.
FAQ
Is the power zone calculator free? Yes, completely, and forever. No email, no account, no paywall on the result.
Do I need a power meter? To train by power zones, yes, since they're watts-based. To find your zones, you just need your FTP, which you can estimate from a 20-minute, 8-minute, or ramp test inside the tool. Without a meter, use heart-rate or pace zones instead.
Is "powerzone calculator" the same thing? Yes. "Power zone calculator," "powerzone calculator," and "FTP zone calculator" all refer to the same tool: turning your FTP into cycling power zones.
The bottom line
A good power zone calculator should take one honest number and give you accurate, usable zones in seconds, for free, without getting in your way. Enter your FTP (or estimate it from a short test), read your seven zones, download the PDF to keep a record, and retest as you improve. Start now with the FTP & power zone calculator, or browse every calculator to set zones for your sport.
Sources. Allen, H. & Coggan, A. Training and Racing with a Power Meter (2nd ed., VeloPress, 2010). Coggan, A. Power Training Levels, TrainingPeaks. FTP-estimation factors (20-minute ×0.95, 8-minute ×0.90, ramp ×0.75) follow the standard field-test protocols described in the same source and by TrainingPeaks.