Displacement & Compression Ratio Calculator Calculate engine displacement and compression ratio using this handy calculator Length units: Inches Millimeters Engine Bore (in) Stroke (in) Number of cylinders Compression ratio (optional) Leave these blank to calculate displacement only. Piston volume: enter a dish or valve reliefs as a positive number and a dome as a negative number. Deck clearance: positive if the piston sits below the deck at TDC, negative if it sticks out above. Combustion chamber (cc) Piston dish / dome (cc) Head gasket bore (in) Head gasket compressed thickness (in) Deck clearance (in) Calculate
