Engine Compression Ratio Calculator Engine Compression Ratio Calculator Bore Unit Millimeters (mm) Centimeters (cm) Inches (in) Stroke Unit Millimeters (mm) Centimeters (cm) Inches (in) Combustion Chamber Volume (cc) Piston Dome Volume (cc, negative for dished) Head Gasket Thickness Unit Millimeters (mm) Centimeters (cm) Inches (in) Deck Height Unit Millimeters (mm) Centimeters (cm) Inches (in) Calculate Compression Ratio