WHP to HP Calculator
Measured at the wheels (dyno reading)
Typical range: 10-20% for RWD, 15-25% for AWD
What is WHP to HP Conversion?
Wheel horsepower (WHP) to engine horsepower (HP) conversion calculates the power output at the engine crankshaft based on measurements taken at the wheels. This conversion accounts for drivetrain losses that occur through the transmission, differential, and other components.
WHP to HP Formula
The formula to convert wheel horsepower to engine horsepower is:
HP = WHP ÷ (1 – (Drivetrain Loss ÷ 100))
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| WHP | Wheel Horsepower | HP | 100-1500 HP |
| Drivetrain Loss | Power loss in transmission | Percentage | 10-25% |
Practical Examples
Example 1: A RWD car with 300 WHP and 15% drivetrain loss:
HP = 300 ÷ (1 – 0.15) = 352.94 HP
Example 2: An AWD vehicle with 250 WHP and 20% loss:
HP = 250 ÷ (1 – 0.20) = 312.5 HP
Key Factors Affecting WHP to HP Conversion
- Drivetrain type (RWD vs AWD vs FWD)
- Transmission efficiency
- Differential type
- Vehicle age and maintenance
- Fluid viscosity
- Ambient temperature
FAQ
How accurate is this calculator?
Accuracy depends on correct drivetrain loss estimation. Use dyno-tested values for your specific vehicle when possible.
Why is AWD drivetrain loss higher?
Additional differentials and drive components create more friction and rotational mass.