CC to HP Conversion Calculator
Small Utility Engine (Lawnmower, etc.) – 17cc per HP
Standard Average Engine – 15cc per HP
Modern Efficient Engine – 12cc per HP
High-Performance / Sport Engine – 8cc per HP
Note: CC to HP is an estimate as displacement doesn't directly measure power output.
Estimated Output:
How to Convert CC to HP
In the world of internal combustion engines, CC (Cubic Centimeters) represents the volume of the cylinders (displacement), while HP (Horsepower) represents the work the engine can perform over time. Because one is a measure of volume and the other is a measure of power, there is no direct mathematical constant that applies to every engine.
The General Rule of Thumb
For most small engines, a widely accepted conversion factor is 15cc to 17cc equals 1 HP. This is common for small motorcycles, scooters, and yard equipment. However, high-performance engines with better compression and fuel mapping can produce significantly more power from the same displacement.
Calculation Examples
- 50cc Scooter: 50 / 15 ≈ 3.33 HP
- 150cc Motorcycle: 150 / 15 = 10 HP
- 250cc Dirt Bike (Efficient): 250 / 12 ≈ 20.8 HP
Key Factors Influencing Horsepower
Two engines with identical CC ratings can have vastly different HP outputs due to:
- RPM (Revolutions Per Minute): HP is a function of torque and RPM. Higher-revving engines generally produce more HP.
- 2-Stroke vs. 4-Stroke: 2-stroke engines typically produce more power per CC because they fire every revolution.
- Compression Ratio: Higher compression leads to more efficient combustion and higher power.
- Fuel Delivery: Turbocharging or fuel injection increases the density of the air-fuel mixture, boosting HP.