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Power Duration Calculator — Sustainable Power Estimates
Estimate sustainable power output for different durations.
How We Calculate This
Power-Duration Estimation
This calculator uses typical power-duration ratios relative to FTP:
- 5-second (neuromuscular): ~340% of FTP (typical maximal sprint; ~335–365% across ability levels — sprinters and track pursuiters run higher)
- 1-minute (anaerobic capacity): ~180% of FTP (typical maximal 1-minute power; ~180–210% for anaerobically strong riders)
- 5-minute (VO2 max): ~120% of FTP
- 20-minute: ~105% of FTP (the inverse of the FTP = 0.95 × 20-minute power rule)
- 60-minute (FTP): ~100% of FTP — FTP is, by definition, the power you can hold for roughly an hour
- 2-hour: ~85% of FTP
Frequently Asked Questions
This is a typical-ratio estimate, not a measured power-duration curve. It applies fixed fractions of your FTP at each duration. Individual variation is significant — sprinters will have higher short-duration power relative to FTP, while time triallists may sustain higher fractions of FTP for longer. For a personalised curve, use 2+ maximal test efforts and fit a critical-power (CP) and W′ model.
The power-duration curve shows the maximum power you can sustain for any given duration. Power decreases as duration increases, following a hyperbolic relationship.
FTP (Functional Threshold Power) is the most commonly tested metric and provides a good anchor point for estimating power at other durations.
Perform dedicated maximal efforts at each duration (5s, 1min, 5min, 20min, 60min) and record the data with a power meter.
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Last updated: February 2026
All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.