Power Duration calculator

Near your peak.
in Seconds.
Between peak and threshold.
in Seconds.
Near threshold.
in Seconds.
Instructions
Use the Xert Fitness Signature calculator to calculate your fitness based upon best-efforts that you have performed from fresh to failure. For example, if you recently performed a 20 minute FTP Test at 250W, fill in 250 for the Power value and 1200 for the Duration value. If you have performed additional tests or have other best effort data from recent activities, enter additional power-duration values. The Xert calculator works best with 3 best-effort power-duration values but will also estimate your fitness and power-duration curve with two or even just one set of values.

Click on Calculate to show the power-duration curve. When logged in, use the Save As My Current Fitness Signature button to save the calculated fitness signature to be your current default Fitness Signature to use in analysis.