FTP Calculator — 20-min, Ramp & 8-min Tests
Enter your best effort from a 20-minute, ramp, or 8-minute test and get your FTP plus all seven Coggan cycling zones in watts. Everything runs in your browser — no account, no upload.
Enter a number to see your FTP and zones.
How the FTP calculator works
Functional Threshold Power (FTP) is the highest power you can sustain for roughly one hour. Three test protocols are widely used to estimate it without actually riding for an hour.
The 20-minute test uses the classic Allen/Coggan protocol: do a hard 20-minute time trial after a proper warm-up and multiply the average power by 0.95. The 5% shave accounts for the fact that most riders can hold slightly more power for 20 minutes than they can for 60.
The ramp test, popularized by TrainerRoad and Zwift, has you hold one-minute steps of increasing power until failure, then takes 75% of your best one-minute power as FTP. It's shorter and less mentally brutal but tends to overestimate FTP for riders with a big anaerobic reserve.
The 8-minute test (2 × 8 min at max sustained effort) is used in TrainingPeaks and by Hunter Allen — average of the two efforts × 0.90. It lands between the 20-min and ramp in duration and reliability.
Once you have an FTP number, the seven Coggan zones are fixed percentages: Active Recovery, Endurance, Tempo, Sweet Spot / Threshold, VO2max, Anaerobic, and Neuromuscular. The calculator computes all of them for you.
FTP (20-min) = 20-min avg power × 0.95 · FTP (ramp) = best 1-min × 0.75 · FTP (8-min) = 8-min avg × 0.90
Frequently asked questions
Which FTP test is most accurate?
For experienced riders, the 20-minute test is the most reliable because the 0.95 factor is validated across thousands of athletes. The ramp test is fine for beginners and for retests, but it can overestimate FTP by 5–15 watts in riders with strong 1–5 minute power. The 8-minute test is rarely used outside TrainingPeaks but gives sensible numbers if you cannot do a 20-minute effort.
How often should I retest my FTP?
Every 6 to 8 weeks during a build phase, or whenever your rate of perceived exertion at a given power starts dropping noticeably. More often than that and you are measuring day-to-day variability rather than adaptation.
Are the Coggan zones the only valid zones?
They are the most widely used, but not the only model. Seiler's polarized 3-zone model, Frank's 4-zone model, and TrainerRoad's simplified 7-zone variant all exist. For structured interval training using power, Coggan's 7-zone model is the default in TrainingPeaks, Zwift, WKO5, and Intervals.icu.
Is the calculator the same as TrainingPeaks?
The math is identical to the Allen/Coggan protocol TrainingPeaks uses. The difference is that our calculator runs entirely in your browser — nothing is uploaded, no account is needed, and the result is instant.
Let Cora apply your FTP automatically
Plugging a number into a calculator is step one. Step two is using that FTP to build targeted workouts week after week and adjusting it when you adapt. Cora, CoreRise's AI coach, does both automatically: she tracks your FTP across test rides, writes every cycling session at the right zone in watts, and updates the number when your training files show you have improved — no manual re-entry needed.