Engine HP Horsepower Change Calculator - ET Method

Calculate Engine HP Change with the ET Method

Uncover the real horsepower gains from your vehicle modifications with our Engine HP Horsepower Change Calculator. Utilizing the Elapsed Time (ET) method, this tool helps automotive enthusiasts and tuners quantify performance increases or decreases based on drag strip times and vehicle weight. Input your before and after ETs to instantly see the HP change.

Formula:

The calculator uses the Elapsed Time (ET) method formula to estimate horsepower:

HP = \frac{\text{Weight}}{\left(\frac{\text{ET}}{5.825}\right)^3}

Where:

  • HP: Horsepower (in hp)
  • Weight: Total vehicle weight including driver (in lbs)
  • ET: Elapsed Time (in seconds, typically for a 1/4 mile race)
  • 5.825: A constant used for 1/4 mile ET calculations

The HP change is then calculated as: HP Change = Final HP - Initial HP

Automotive and Tools

1/4 Mile ET : Estimate Your Quarter Mile Elapsed Time

Go to Calculator

1x1 Matrix Multiplication

Go to Calculator

3D Distance : Find Distance Between Two Points in 3D Space

Go to Calculator

5x5 Matrix Multiplication

Go to Calculator

65th Percentile : Find the 65th Percentile Online

Go to Calculator

75th Percentile : Quickly Find Q3 for Your Dataset

Go to Calculator