This program calculates approximate rear wheel horsepower based on actual vehicle weight (including driver), and quarter mile elapsed time and trap speed.

There are two formulae. One uses weight and e.t, the other uses weight and speed. This program does both and averages them.

The "Approx Engine HP" assumes 25% drivetrain losses. Obviously, there are a lot of variables unaccounted for, so don't use this for bragging rights.