Displacement is the total volume the pistons sweep — the headline size of an engine.
Displacement = (π ÷ 4) × Bore² × Stroke × Cylinders
Where
| Bore | Cylinder diameter |
| Stroke | Distance the piston travels |
| Cylinders | Number of cylinders |
Worked example
A 3.5 in bore, 3.0 in stroke, 6-cylinder engine: 0.7854 × 3.5² × 3.0 × 6 = 173 in³, about 2.8 L.
Unit conversion: 1 liter = 61.0 in³, and displacement in cc divided by 1,000 gives liters.
Use the Engine Displacement calculator in the automotive calculators.