Engine Horsepower Calculator
The following two calculators can be used to estimate the engine horsepower of your vehicle based on the weight, the time, and the speed to finish a quarter mile run. The weight to be used here should include the mass of the vehicle, the driver, the passenger, and other load. The results of these two calculators are estimations only.
The ET Method
This method uses the vehicle weight and the elapsed time (ET) to finish a quarter mile (402.3 meters) on the formula of Horsepower = Weight/(ET/5.825)3.
The Trap-speed Method
This method uses the vehicle weight and the speed at which the vehicle finished a quarter mile (402.3 meters) on the formula of Horsepower = Weight*(Speed/234)3. The speed to be used here should be the finishing speed at the quarter mile point, not the average speed.