When it comes to measuring a car’s power, wheel horsepower (WHP) and engine horsepower (HP) are two important terms. WHP is the power measured at the wheels, while HP refers to the power produced by the engine before any losses. Because some power is lost through the drivetrain, engine horsepower is always higher than wheel horsepower.
WHP to HP Calculator
300 WHP = 375.0 HP (All-Wheel Drive (AWD), 20% loss)
HP = WHP ÷ (1 – Loss/100)
HP = 300 ÷ (1 – 20/100)
HP = 300 ÷ 0.80
HP = 375.0
How to Convert WHP to HP
The conversion is simple once you know the drivetrain loss. The formula is:
Conversion Formula
HP = WHP ÷ (1 – Drivetrain Loss)
Drivetrain loss is usually given as a percentage. For example, if the drivetrain loss is 15%, you use 0.15 in the formula.
Example Calculation
If your car has 300 WHP and a drivetrain loss of 15%, the engine horsepower would be:
HP = 300 ÷ (1 – 0.15) = 300 ÷ 0.85 ≈ 353 HP
Why This Matters
This quick calculation helps you estimate the actual power your engine produces, giving you a clearer picture of your car’s performance beyond just the wheel measurements.