FTP Estimator: Turning a 20-Minute Test Into Training Zones
Functional threshold power anchors most cycling training zones. A 20-minute test times 0.95 is the common shortcut to it.
What is the FTP Estimator?
Enter your best average power over 20 minutes. The tool estimates FTP as 95% of that effort, a widely used rule of thumb, and prints the usual seven training zones. This is an estimate: a lab test or a longer effort can give a different number, and zones are guides, not prescriptions.
How to use it
- Ride a hard, steady 20-minute effort and note average power.
- Enter that power in watts.
- Click Estimate FTP.
Worked example
A 250-watt 20-minute effort estimates FTP at 237.5 watts, with Zone 2 spanning about 133 to 178.13 watts.
What FTP does a 250-watt 20-minute test give?
About 238 watts (250 x 0.95), which is an estimate, not a lab measurement.
Frequently asked questions
Is 95% exact?
No. It is a rule of thumb; some riders test a little above or below it.
Should I train only by these zones?
Zones are guides. Feel, fatigue, and a coach's plan still matter.