Cycling FTP & Power Zones Calculator

Cycling FTP & Power Zones Guide

What is FTP?

FTP (Functional Threshold Power): the highest average power you can sustain for one hour. Originally defined by Andy Coggan, now standard for power-based cycling training. Measured in watts. Typical values: untrained male 100-150W. Recreational male 150-225W. Strong club cyclist 250-350W. Elite male 380-450W. Tour de France level 5.5-7 W/kg. World Tour pros sustain 400-450W FTP at 60-75 kg = 6.0-7.0 W/kg. Why FTP matters: defines your training zones. All power-based training is calibrated as a percentage of FTP, which is why establishing an accurate number matters more than any single training session.

What do I need to know about FTP Test Methods?

20-minute test (most common): warm-up + 20 minutes max sustained effort. FTP = average power × 0.95. The 5% reduction accounts for the difference between 20min and 60min sustainable power. Ramp test (Zwift, TrainerRoad style): gradual power increase, ~3-5W per second, until failure. FTP = peak 1-minute power × 0.75. Less accurate for some riders but easier to execute. 60-minute test (gold standard): all-out 60 minute time trial. Average power = FTP. Physically and mentally brutal — most riders avoid repeating it more than once every few months, preferring shorter, less gruelling test protocols in between.

What should I know about Coggan Power Zones?

Z1 Active Recovery: <55% FTP. Easy spinning, recovery rides. Heart rate < 68% max. Z2 Endurance: 56-75% FTP. Most training time here. Long rides, base building. Aerobic system. Heart rate 69-83% max. Z3 Tempo: 76-90% FTP. Moderate effort. 1-3 hour rides. Heart rate 84-94% max. Z4 Lactate Threshold: 91-105% FTP. Race pace. 10-60 minute efforts. Heart rate 95-105% max. Z5 VO2max: 106-120% FTP. 3-8 minute intervals. Maximal aerobic system. Z6 Anaerobic Capacity: 121-150% FTP. 30-second to 3-minute efforts, used sparingly since this zone is extremely taxing on both the muscular and nervous systems.

What's the key thing to understand about Power Meters and Indoor Trainers?

Power meters (pedals, cranks, hubs): direct measurement. Most accurate. Brands: Garmin Vector pedals, Stages cranks, Quarq, Powertap hubs. £400-1,500. Smart trainers (Wahoo Kickr, Tacx Neo, Elite Direto): measure power at trainer. Indoor accuracy excellent, cross-device comparison usually within 2-3%. Free 30-day Zwift trial: includes ramp test. Great way to estimate FTP without buying equipment. Mobile-only estimation: virtual power on Zwift with non-smart trainer (uses power curve from speed).

What's the key thing to understand about What FTP Means and Why It Matters?

Functional Threshold Power (FTP) is defined as the highest average power output, in watts, that a cyclist can sustain for approximately one hour, and it has become the standard reference point for structuring cycling training because nearly every other training zone and pacing decision can be expressed as a percentage of it. FTP corresponds closely to a cyclist's lactate threshold — the exercise intensity at which lactate begins accumulating in the blood faster than the body can clear it — which is why it functions as such a useful single number: below FTP, effort can generally be sustained for a long time without rapidly accumulating fatigue, while above FTP, fatigue accumulates increasingly quickly the higher above threshold the effort goes, limiting how long that higher intensity can be held. Because directly testing a true one-hour maximal effort is both physically brutal and mentally very difficult to pace accurately, most cyclists estimate FTP from shorter, more manageable test protocols instead — commonly a 20-minute maximal effort test, with the result multiplied by approximately 0.95 (since most riders can hold a slightly higher power for 20 minutes than they could sustain for the full hour), or increasingly, ramp tests performed on smart trainers that estimate FTP from the power curve of a steadily increasing effort test to exhaustion.

What do I need to know about Power-Based Training Zones?

Once FTP is established, it is used to define a structured set of training zones, each targeting different physiological adaptations, typically following the widely used Coggan power zone model. Zone 1 (Active Recovery, below ~55% of FTP) is easy riding for recovery between harder sessions; Zone 2 (Endurance, ~56-75% of FTP) is the foundation of aerobic base training, sustainable for multiple hours and central to most structured cycling plans; Zone 3 (Tempo, ~76-90% of FTP) is a moderately hard, 'comfortably uncomfortable' effort; Zone 4 (Threshold, ~91-105% of FTP) sits right around FTP itself and is specifically used to raise the threshold over time; Zone 5 (VO2 Max, ~106-120% of FTP) targets maximal aerobic capacity through short, very hard intervals; and Zones 6-7 (Anaerobic Capacity and Neuromuscular Power, above ~121% of FTP) target short, extremely intense efforts like sprints, which draw on energy systems largely separate from aerobic fitness. Training with power zones rather than perceived effort or heart rate alone is valuable because power output is an objective, immediate measure of the actual work being done, unaffected by the lag and external factors (heat, caffeine, fatigue, stress) that affect heart rate response — meaning a power meter shows exactly how hard a cyclist is working in real time, rather than how hard their heart happens to be working to support that effort, which can vary for reasons unrelated to the pedalling intensity itself.

How Often Should You Retest FTP?

FTP changes as fitness changes, so training zones calculated from an outdated number gradually stop matching current ability, either making training too easy (if fitness has improved since the last test) or unsustainably hard (if fitness has dropped, for example after time off). Most coaches recommend retesting every six to eight weeks during a focused training block, which is roughly the timeframe over which a meaningful FTP change is likely to have occurred from consistent training, while being frequent enough to keep zones relevant without constantly interrupting training with taxing test efforts. Outside a specific key training block — during a lower-intensity base period, for example — testing less frequently, perhaps every couple of months, is reasonable since big FTP changes are less likely during that phase. There are also non-test ways to sense that FTP has likely shifted and a retest is warranted: workouts at zones that used to feel appropriately hard starting to feel noticeably easier (suggesting FTP has risen) or noticeably harder (suggesting a drop, often after illness, a long break, or a period of overreaching) are a practical day-to-day signal. Many modern power meters, head units and training platforms also estimate FTP continuously from ride data without a dedicated test, which can't fully replace a focused test for precision but is useful for spotting a meaningful trend between formal tests, prompting a proper retest at a sensible moment rather than waiting out a fixed calendar interval regardless of how training is going.

The Power-Duration Curve: FTP as a Percentage of Shorter Efforts

FTP sits at roughly the one-hour point on an individual's power-duration curve — the relationship between how long an effort is sustained and the maximum average power possible for that duration. Shorter efforts allow meaningfully higher power relative to FTP, which is why a 5-minute power number is a poor substitute for FTP when setting training zones.

This is the physiological basis for the 0.95 correction applied to a 20-minute test effort: at the 20-minute duration, trained cyclists can typically hold about 105% of what they could sustain for a full hour, so multiplying the 20-minute average by 0.95 brings the estimate back down to the true one-hour (FTP) figure.

Why FTP Matters More Than Maximum Power

Peak sprint power (achievable for only a few seconds) says little about endurance performance, which is why FTP — a sustainable one-hour figure — rather than peak watts is the number used to set training zones and compare aerobic fitness between riders; two cyclists with identical sprint power can have very different FTPs depending on their aerobic conditioning, and it is FTP, not sprint power, that predicts how they will perform over a long climb or time trial.