# What is the engine displacement?

Computes engine displacement from bore, stroke and the number of cylinders, in cubic centimetres (cc), litres and cubic inches.

- Page: https://www.acalculator.org/physics/engine-displacement-calculator
- JSON spec: https://www.acalculator.org/physics/engine-displacement-calculator.json
- Version: 1c1fdeb76781

## Default answer

Example with the default inputs (Bore 4 in, Stroke 3.48 in, Cylinders 8): A 8-cylinder engine with this bore and stroke displaces 5,733 cc (5.73 L, 349.8 in³).

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| bore | Bore | The diameter of one cylinder. |
| stroke | Stroke | How far the piston travels from the bottom to the top of the cylinder. |
| cyl | Cylinders | How many cylinders the engine has. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| cc | Displacement (cc) | The swept volume of all cylinders, in cubic centimetres. |
| liters | Displacement (L) | The same volume in litres: cc ÷ 1,000. |
| cubicInches | Displacement (in³) | The same volume in cubic inches: cc ÷ 16.387064. |
| perCylinder | Per cylinder (cc) | The swept volume of one cylinder: π ÷ 4 × bore² × stroke. |

## Method

Displacement = π ÷ 4 × bore² × stroke × cylinders; litres = cc ÷ 1,000; cubic inches = cc ÷ 16.387064.

## Assumptions

- Displacement is the swept volume only: the combustion chamber above the piston at the top of its stroke is not included.
- Every cylinder has the same bore and stroke.
- 1 in = 2.54 cm exactly, so 1 in³ = 16.387064 cm³.

## Worked examples

1. bore = 0.1016, stroke = 0.088392, cyl = 8 gives cubicInches = 349.847758, cc = 5,732.977599, liters = 5.732978. Source: Cylinder volume π × r² × h (OpenStax, Prealgebra 2e, §9.6 Solve Geometry Applications: Volume and Surface Area). https://openstax.org/books/prealgebra-2e/pages/9-6-solve-geometry-applications-volume-and-surface-area.
2. bore = 0.086, stroke = 0.086, cyl = 4 gives cc = 1,998.228857, perCylinder = 499.557214. Source: Cylinder volume π × r² × h (OpenStax, Prealgebra 2e, §9.6 Solve Geometry Applications: Volume and Surface Area). https://openstax.org/books/prealgebra-2e/pages/9-6-solve-geometry-applications-volume-and-surface-area.
3. bore = 0.1, stroke = 0.127324, cyl = 1 gives cc = 1,000, liters = 1. Source: Cylinder volume π × r² × h (OpenStax, Prealgebra 2e, §9.6 Solve Geometry Applications: Volume and Surface Area). https://openstax.org/books/prealgebra-2e/pages/9-6-solve-geometry-applications-volume-and-surface-area.

## FAQ

### How do I calculate engine displacement?

Each cylinder sweeps a cylinder of air as the piston moves: π ÷ 4 × bore² × stroke. Multiply by the number of cylinders. A V8 with a 4.00 in bore and 3.48 in stroke displaces π ÷ 4 × 4² × 3.48 × 8 = 349.85 in³, the "350" of a small-block engine.

### How do I convert cc to cubic inches?

Divide by 16.387064, because 1 in = 2.54 cm exactly and 2.54³ = 16.387064. So 5,733 cc is 349.85 in³, and 2,000 cc is 122.05 in³.

### How many cc is a liter?

One liter is 1,000 cm³, so a 1,998 cc engine is a 2.0 L engine. Makers round the liters to one decimal in the model name.

### What is the difference between bore and stroke?

The bore is the diameter of the cylinder. The stroke is how far the piston travels from the bottom of its path to the top. An engine with the same bore and stroke (86 × 86 mm) is called "square".

### Does displacement include the combustion chamber?

No. Displacement is only the volume the piston sweeps. The space left above the piston at the top of its stroke is the clearance volume; together they set the compression ratio.

### Does a bigger displacement mean more power?

Usually more torque and power at the same engine speed, because each turn moves more air. Turbochargers, engine speed and design change the power a given size makes, so displacement alone does not give horsepower.

## Sources

- OpenStax, Prealgebra 2e, §9.6 Solve Geometry Applications: Volume and Surface Area (volume of a cylinder V = π r² h). https://openstax.org/books/prealgebra-2e/pages/9-6-solve-geometry-applications-volume-and-surface-area (retrieved 2026-10-01)
- NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: 1 in = 2.54 cm; 1 in³ = 16.387064 cm³; 1 L = 1,000 cm³. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c (retrieved 2026-10-01)