DIY Cost Tools
Engine Displacement Calculator
Calculate total engine displacement in cubic centimetres, litres, and cubic inches from bore, stroke, and cylinder count. Start with the prefilled example or enter your dimensions.
Bore and stroke must be positive, no more than 10,000 mm. Cylinder count must be an integer from 1 to 64. All fields are required.
How to use
Measure piston stroke from top dead center to bottom dead center. Use millimetres for length fields and the specified units for other inputs. Select Calculate after changing values. Default results appear on page load. Outputs use up to ten significant digits; actual measurement accuracy may be much lower.
Formula and explanation
V = (π/4)B²SN. With bore B and stroke S in millimetres, divide V by 1,000 for cubic centimetres (cc), then by another 1,000 for litres. Divide cc by 16.387064 for cubic inches. N is cylinder count. Bore is diameter, not radius.
Worked example
An 86 mm bore, 86 mm stroke, four-cylinder engine has about 1,998.2296 cc, or 1.99823 L, of swept displacement.
Limitations and professional guidance
Assumes identical circular bores and equal stroke in every cylinder of a reciprocating piston engine. Swept displacement excludes combustion-chamber clearance volume. Not a rotary-engine equivalency tool. Displacement alone does not predict horsepower, torque, fuel economy, compression ratio, or legal engine classification. Confirm measured dimensions and manufacturer specifications for actual engine work.
Frequently asked questions
Does a four-stroke cycle double displacement?
No. Displacement is geometric swept volume, independent of how many crank revolutions the combustion cycle takes.
Can I enter inches?
Multiply bore and stroke in inches by 25.4 to obtain millimetres.
Why is a 2.0 L engine slightly under 2,000 cc?
Marketing engine sizes are often rounded; this calculator uses the exact entered dimensions.
Does an overbore increase displacement?
Yes, when stroke and cylinder count are unchanged. Displacement grows with bore squared.
Review notes
Reviewed October 1, 2026. Formulas were checked against published engine geometry references and independently evaluated for default and boundary examples. Blank, nonfinite, negative, and out-of-range inputs were tested. Educational estimates only.