WHP to HP Calculator


This WHP to HP calculator provides an estimation of the engine’s horsepower (HP) from the given wheel horsepower (WHP), taking into account the expected drivetrain losses. The percentages of loss are generalized and based on averages, so it’s vital to understand that these figures might not apply universally to all vehicles.

The drivetrain loss is a measure of how much power is consumed or lost due to the resistance within the vehicle’s drivetrain components before it reaches the wheels. The efficiency of this transfer can differ based on the type of drivetrain and individual vehicle specifications.

Below are standard average drivetrain loss percentages:

  • Front-wheel drive (FWD): 10% loss
  • Rear-wheel drive (RWD): 15% loss
  • All-wheel drive (AWD): 25% loss

These figures serve as a general guideline and can differ for particular vehicle models, brands, or conditions. For precise conversions, it’s always best to refer to specific data or undertake dynamometer tests.

How It Works: For a quick overview, if a car outputs 100 WHP and has an associated drivetrain loss of 25% for an AWD, the calculation would be:

Engine HP = WHP / (1 – drivetrain loss percentage) In this case: Engine HP = 100 / 0.75 Resulting in: Engine HP = 133.33

However, always remember that this is a basic calculation and may not represent the exact power due to other influencing factors.