Convert Milliliters to US Gallons

Formula

gal (US) = mL × 0.0002641720523581

or gal (US) = mL ÷ 3785.411784

Derivation from SI units:

• 1 mL = 10⁻³ L = 1 cm³ = 10⁻⁶ m³
• 1 US gal = 231 in³ = 231 × (0.0254 m)³ = 0.003785411784 m³
• 1 mL = 0.000001 m³ ÷ 0.003785411784 m³ per gal (US) = 0.0002641720523581 gal (US)

Both units are defined exactly, so the factor is exact. Milliliter definition: milliliter; US Gallon definition: US gallon.

Worked examples

1. A reading of 15 mL converts to 0.003962580785 gal (US).
   15 mL × 0.0002641720524 = 0.003962580785 gal (US)
2. A value of 250 mL is 0.06604301309 gal (US).
   250 mL × 0.0002641720524 = 0.06604301309 gal (US)

Where it's used

Milliliters are used for medicine doses and syringes, while US gallons appear in fuel, water and chemical volumes in the US. Both measure volume (capacity), so the conversion is a fixed factor.

Milliliter 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 8, litre with SI prefix milli.
• 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 [U.S.] (gal)".
• NIST Handbook 44, Appendix C: General Tables of Units of Measurement, National Institute of Standards and Technology , Appendix C.

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