Engine Displacement Calculator
Enter bore, stroke and cylinders to get total displacement in cc, liters and CID — plus each cylinder's swept volume.
Open calculatorLast updated: 2026-09-15
How the calculation works
- Each cylinder sweeps a cylinder of bore × stroke; π/4 × d² × h gives its volume.
- Multiply by cylinder count for total displacement; the tool converts to liters and cubic inches.
Worked example
Interpreting the result
Displacement sets the air an engine can theoretically ingest per cycle — power scales with it, airflow, and volumetric efficiency. The bore/stroke ratio shapes the character: oversquare engines rev higher (short stroke, big valves fit), undersquare make low-end torque. Oversizing bore without flow work buys compression but not power.
Assumptions
- Cylindrical combustion space swept by the piston (chamber volume excluded — see the compression ratio calculator).
- Nominal bore and stroke at room temperature.
Limitations
- Wankel engines use a different volume convention (chamber × 2 typically cited).
- Does not include gasket/deck clearance volume.
Four-cylinder displacement (litres) by bore and stroke
| Bore | 70 mm stroke | 80 mm stroke | 90 mm stroke |
|---|---|---|---|
| 70 mm | 1.08 | 1.23 | 1.39 |
| 76 mm | 1.27 | 1.45 | 1.63 |
| 82 mm | 1.48 | 1.69 | 1.90 |
| 86 mm | 1.63 | 1.86 | 2.09 |
| 90 mm | 1.78 | 2.04 | 2.29 |
| 96 mm | 2.03 | 2.32 | 2.61 |
Displacement = π ÷ 4 × bore² × stroke × cylinders.
The same 86 × 86 mm cylinder with different cylinder counts
| Cylinders | Displacement (L) | Displacement (cc) | Displacement (in³) |
|---|---|---|---|
| 3 | 1.50 | 1,499 | 91.5 |
| 4 | 2.00 | 1,998 | 121.9 |
| 5 | 2.50 | 2,498 | 152.4 |
| 6 | 3.00 | 2,997 | 182.9 |
| 8 | 4.00 | 3,996 | 243.9 |
Bore, stroke and what the ratio tells you
Bore is the cylinder diameter and stroke is how far the piston travels. An engine whose bore is larger than its stroke is called oversquare; one with a longer stroke than bore is undersquare. In general terms, oversquare designs leave room for larger valves and tolerate higher engine speeds, while undersquare designs tend to favour torque at lower speeds. Real engines depend on much more than this ratio.
Worked scenario: an 86 × 86 mm four-cylinder
The calculator gives 1,998 cc, that is 2 L, with 499.6 cc per cylinder. Manufacturers round this to a marketing figure such as 2.0 L, so a computed value will often sit a little off the badge.
Mistakes to avoid
- Entering inches in a field that expects millimetres, or the other way round.
- Using the cylinder count of the whole engine for one bank of a V engine.
- Treating the result as the engine's compression or power. Displacement is volume only.
Frequently asked questions
How do I convert cc to cubic inches?
Multiply cc by 0.061 (or divide by 16.387). A 350 CID Chevy is 5,735 cc = 5.7 L; a 2.0 L engine is 122 CID.
Does displacement equal power?
No — it sets the ceiling. Volumetric efficiency, breathing, compression and RPM decide how much of that ceiling the engine reaches. A 2.0 L turbo can outperform a 3.0 L NA engine.