The formula
cm³ = in³ × 16.387064
Where the factor comes from — each unit by its definition, then its size in SI:
1 in³ = in³ = 1.6387064 × 10⁻⁵ m³1 cm³ = cm³ = 1 × 10⁻⁶ m³
Dividing the two SI sizes gives the factor: 16.387064, exact — every step above is a definition, not a measurement. The reverse factor is 0.0610237440947.
The cubic metre is the SI unit of volume; the litre is exactly one thousandth of it. The US and UK gallons are different sizes, which is why a fuel-economy figure in mpg depends on which country printed it.
Worked examples
- A soft-drink bottle (2 L): 122.047 in³ = 2,000 cm³ — 122.047 × 16.387064 = 2,000
- A paint bucket (5 US gal): 1,155 in³ = 18,927.1 cm³ — 1,155 × 16.387064 = 18,927.1
- A water tank (1 m³): 61,023.7 in³ = 1,000,000 cm³ — 61,023.7 × 16.387064 = 1,000,000
- A drinks can (330 mL): 20.1378 in³ = 330 cm³ — 20.1378 × 16.387064 = 330
Frequently asked questions
How many cubic centimetres is 1 in³?
1 in³ = 16.387064 cm³, exactly, from the unit definitions.
How do I convert cubic centimetres back to cubic inches?
Divide by 16.387064 — or multiply by 0.0610237440947: 1 cm³ = 0.0610237440947 in³.