Functional Threshold Power (FTP) is the highest average power you can sustain for approximately one hour. It is the gold standard for measuring cycling fitness and setting training zones.

Why multiply 20-minute power by 0.95?

The 20-minute test protocol assumes your FTP is 95% of your best 20-minute power. This accounts for the fact that most people can sustain slightly more power for 20 minutes than for a full hour.

How often should I test FTP?

Test every 6-8 weeks, or at the start and end of a training block. More frequent testing is unnecessary and disruptive to training.

FTP varies hugely. Untrained: 1.5-2.0 W/kg. Recreational: 2.0-3.0 W/kg. Club racer: 3.0-4.0 W/kg. Cat 1/2: 4.0-5.0 W/kg. Professional: 5.5-7.0 W/kg.

Which test protocol is best?

The 20-minute test is most popular and reliable. The ramp test is easier to execute but can overestimate FTP for some riders. The 60-minute test is the most accurate but extremely demanding.

BikeCalcs

FTP Calculator — Functional Threshold Power

Estimate your FTP from different test protocols.

Test Protocol

Average Power

Average power during the test effort

Body Weight

How We Calculate This

FTP Estimation Methods

20-minute test: FTP = Average Power x 0.95
8-minute test: FTP = Average Power x 0.90
Ramp test: FTP = Last completed minute average x 0.75
60-minute test: FTP = Average Power (direct measurement)

The multiplier accounts for the relationship between the test duration and the one-hour effort FTP represents. Shorter tests require larger reductions.

Frequently Asked Questions

Related Calculators

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Calculate heart rate training zones from max or threshold HR.

Power Zone Calculator

Calculate power-based training zones from your FTP.

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Estimate calories burned cycling based on power, weight and duration.

TSS Calculator

Calculate Training Stress Score from power and duration.

Training Load Calculator

Track acute and chronic training load over time.

Last updated: 2025-02-20

All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.