Convert Cubic Centimeters to Imperial Gallons

Formula

gal (imp) = cm³ × 0.0002199692482991

or gal (imp) = cm³ ÷ 4546.09

Derivation from SI units:

• 1 cm³ = (0.01 m)³ = 10⁻⁶ m³ = 1 mL
• 1 imp gal = 4.54609 L = 0.00454609 m³ (exact, by definition)
• 1 cm³ = 0.000001 m³ ÷ 0.00454609 m³ per gal (imp) = 0.0002199692482991 gal (imp)

Both units are defined exactly, so the factor is exact. Cubic Centimeter definition: cubic centimeter; Imperial Gallon definition: imperial gallon.

Worked examples

1. A reading of 10 cm³ converts to 0.002199692483 gal (imp).
   10 cm³ × 0.0002199692483 = 0.002199692483 gal (imp)
2. A value of 500 cm³ is 0.1099846241 gal (imp).
   500 cm³ × 0.0002199692483 = 0.1099846241 gal (imp)

Where it's used

Cubic Centimeters are used for engine displacement (e.g. 125 cc, 1600 cc), while imperial gallons appear in fuel economy in the UK (miles per gallon). Both measure volume (capacity), so the conversion is a fixed factor.

Cubic Centimeter to other volume units

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 2 with SI prefix centi.
• Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "gallon [Canadian and U.K. (Imperial)]".

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.