Use this tool to calculate the compression ratio of your engine, aiding in understanding its efficiency and performance.
Compression Ratio Calculator
How to Use the Calculator:
Enter the following values:
- Bore Diameter: The diameter of the cylinder bore in centimeters.
- Stroke Length: The length of the piston stroke in centimeters.
- Combustion Chamber Volume: The total volume of the combustion chamber in cubic centimeters (cc).
- Piston Dome Volume: The volume of the piston dome in cc. Use negative values for dome pistons.
- Gasket Thickness: The thickness of the head gasket in centimeters.
- Gasket Diameter: The diameter of the head gasket in centimeters, which should match the bore size.
- Deck Height: The distance that the piston is down in the cylinder at top dead center (TDC) in centimeters.
After filling in the values, click the “Calculate” button to see the compression ratio in the “Result” field.
How it Calculates the Result:
The compression ratio is calculated by dividing the total cylinder volume (when the piston is at the bottom of its stroke) by the clearance volume (when the piston is at top dead center). The total volume includes the combustion chamber volume, piston dome volume, the volume of the space above the piston when it’s at TDC (combustion chamber volume + head gasket volume + deck height volume), and the displacement of one cylinder. The clearance volume only includes the first three of these components.
Limitations:
This calculator assumes that the input values are accurate and the engine has a simple cylindrical bore and piston. It may not be accurate for engines with non-standard shaped combustion chambers or pistons, or in cases where precise measurements are not available.