Engine Displacement Calculator
Calculate engine displacement from bore, stroke, and cylinder count. Results are shown in cubic centimetres (cc), litres (L), and cubic inches (ci). You can enter measurements in either millimetres or inches; select the unit below. This calculator uses the standard piston-volume formula cited in SAE technical literature and automotive engineering textbooks.
Engine displacement formula
Displacement (cc) = (pi / 4) x Bore_mm^2 x Stroke_mm x Cylinders
Litres = cc / 1,000
Cubic inches = cc / 16.3871
Each cylinder sweeps a volume equal to the area of the bore circle (pi/4 x d^2) multiplied by the stroke length. Summed over all cylinders, this gives total displacement. This is the standard formula from SAE International engineering publications and engine manufacturer specifications.
Common engine displacement reference values
- Kei car (Japan): up to 660 cc (0.66 L) with up to 3 cylinders.
- Economy 4-cylinder: 1.4 L to 2.0 L (1,400 to 2,000 cc).
- Mid-size V6: 2.5 L to 3.5 L (2,500 to 3,500 cc, 153 to 214 ci).
- V8 (US muscle car / truck): 4.6 L to 6.2 L (281 to 379 ci).
- Classic small-block Chevy 350: 5.7 L (5,735 cc, 350 ci) with 4.00 in bore and 3.48 in stroke.
- Large diesel truck: 6.7 L (6,700 cc) for modern Ford Power Stroke and GM Duramax.
Engine displacement calculator: frequently asked questions
What is engine displacement?
Engine displacement is the total volume swept by all pistons in all cylinders during a single stroke, measured from bottom dead centre to top dead centre. It is expressed in cubic centimetres (cc), litres (L), or cubic inches (ci). Displacement is a primary indicator of an engine's size and, along with compression ratio and other factors, its potential power output.
What is the engine displacement formula?
Displacement (cc) = (pi / 4) x Bore_mm^2 x Stroke_mm x Number_of_cylinders. This is the standard geometric formula used in SAE technical papers and by engine manufacturers worldwide. The bore is the cylinder diameter; the stroke is the distance the piston travels between bottom dead centre and top dead centre.
How do I convert cc to litres and cubic inches?
1 litre = 1,000 cc, so litres = cc / 1,000. For cubic inches: 1 cubic inch = 16.3871 cc, so cubic inches = cc / 16.3871. A 2.0 litre engine is 2,000 cc or approximately 122 cubic inches. Older US engine specs often used cubic inches (e.g., a 302 ci engine is 4.95 litres).
Does more displacement always mean more power?
Not necessarily. Displacement sets a theoretical ceiling on how much air-fuel mixture can be burned per cycle, which limits power potential. However, forced induction (turbocharging, supercharging), compression ratio, valve timing, and fuel system all dramatically affect actual power output. A modern turbocharged 2.0L engine can produce more power than a naturally aspirated 5.0L engine from 30 years ago.
Why does displacement matter for registration and taxes?
Many countries calculate vehicle registration fees, road taxes, and import duties based on engine displacement. In the UK, older vehicle tax bands used displacement. In Japan, vehicles under 660 cc (kei cars) qualify for significant tax and regulatory advantages. In many Australian states, registration fees scale with displacement. The US does not use displacement as a primary tax basis, but CAFE fuel economy standards indirectly penalise larger engines.
Official sources
- SAE International Technical Papers on engine specifications: sae.org/publications/technical-papers.
- NIST SP 330 (SI unit conversion factors for cubic measure): nist.gov SP 330.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.