Horsepower Calculator
Calculate engine horsepower using multiple methods and specifications
Calculation Settings
Select calculation method and measurement units
Most accurate method using dyno measurements
Pound-feet (lb-ft)
Revolutions per minute
Optional Vehicle Information
Horsepower Formula
Torque & RPM Method:
HP = (Torque × RPM) ÷ 5,252
Most accurate for engines with dyno data
Power Conversion:
1 HP = 745.7 Watts = 0.746 kW
Include efficiency losses for real-world power
Kinetic Energy:
HP = (Weight × Velocity²) ÷ (375 × Time)
Estimates power from acceleration data
Performance Factors
Engine Factors:
- Displacement (larger = more power potential)
- Compression ratio (higher = more efficiency)
- Fuel octane rating and type
- Forced induction (turbo/supercharger)
Environmental Factors:
- Altitude (higher = less air density)
- Temperature (cooler = denser air)
- Humidity (affects combustion)
- Atmospheric pressure