Cycling FTP Calculator (20-Minute Test)
Turns average power from an all-out 20-minute effort into Functional Threshold Power in watts, the 95% estimate used to set cycling training zones.
FTP (W)
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How the 20-min FTP test works
FTP (Functional Threshold Power) is the maximum power a cyclist can sustain for roughly one hour. The Andrew Coggan protocol avoids a full 60-min effort by doing a 20-minute all-out test and applying FTP = average_20min_power × 0.95. Watts-per-kg (W/kg) normalises for body weight: under 2 W/kg is beginner, 3–3.5 trained amateur, 4 strong amateur, 5+ elite, and 6+ is Tour de France pro territory. Devices like Garmin Edge, Wahoo Bolt, and smart trainers (Wahoo Kickr, Tacx Neo) integrated with Zwift or TrainerRoad measure power directly.
Example: 20-min average power of 250 W → FTP = 250 × 0.95 = 237 W.
Applications
Zwift and TrainerRoad training plans, Strava performance analysis, training-zone definition (Z2 endurance, Z4 threshold, Z6 VO2max), relative power/weight comparison between riders, and progress tracking through the season.
FAQ
Why 95 % of 20 min? A 20-min all-out effort recruits anaerobic capacity above true FTP; the 0.95 factor empirically removes that contribution.
How often should I re-test? Every 4–8 weeks during structured training, or when ratings of perceived exertion at current zones drop.
FTP vs Critical Power? Critical Power (CP) uses 3-min and 12-min tests and is more precise; FTP is the practical, widely-adopted approximation.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.