Enter the engine horsepower and select the drive system to determine a car’s wheel horsepower.

Wheel Horsepower Formula

The following formula is used to calculate the amount of horsepower delivered to the wheels of a car.

WHP = EHP / DTLF

  • Where WHP is the wheel horsepower
  • EHP is the engine horsepower
  • LF is the drive train loss factor
    • front wheel drive = 1.1
    • rear wheel drive = 1.15
    • all wheel drive = 1.2

What is wheel horsepower?

Definition:

Wheel horsepower is a measure of the horsepower delivered to the wheels of a car by the engine after the drivetrain loss has been taken into account.

The drive train loss is a loss of power that the wheels receive due to friction and other inefficiencies through the drive train.

How to calculate wheel horsepower?

Example:

The following example outlines the steps and information required to calculate the horsepower received by wheels after drivetrain loss has been subtracted.

First, determine the total engine horsepower output. In this example, the engine of the car can output a maximum of 600 horsepower (hp).

Next, determine the drive train system. In this example, the drive train is a front-wheel-drive system.

Next, determine the drive-train loss factor. In this case, the loss factor is 1.1 as shown in the formula above.

Finally, calculate the wheel horsepower:

WHP = EHP / DTLF

WHP = 600 / 1.1

WHP = 545 .45 horsepower