Engine displacement calculator

Enter bore diameter, piston stroke and the number of identical cylinders. Changing the length unit reinterprets the entered dimensions. Displacement is the swept volume, excluding the combustion chamber.

V = π × bore² × stroke × cylinders / 4

Four cylinders with 80 mm bore and 90 mm stroke displace 1809.557 cm³, or about 1.810 litres. Use measured dimensions for a bored or stroked engine.

The result above uses these exact values. This snapshot is included when the page is printed so the output can be checked against the original measurements.

Length unit

mm

Cylinder bore

80 mm

Piston stroke

90 mm

Cylinder count

4

Primary result: Total displacement: 1809.55737 cm³.

• Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
• Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
• When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.

Supports 1–64 identical circular cylinders in a reciprocating piston engine. It does not calculate rotary-engine equivalence, compression ratio, power or usable fluid capacity.