Gallons to Liters Converter

How to convert gallons to liters

1 gallon = 3.785411784 liters. To convert gallons to liters, multiply by 3.785411784. A US liquid gallon is 231 cubic inches, exactly 3.785411784 L. A liter is one cubic decimeter (1,000 cm³).

Worked examples

• 1 gallon = 3.78541 L (1 × 3.7854118)
• 5 gallons = 18.9271 L (5 × 3.7854118)
• 55 gallons = 208.198 L (55 × 3.7854118)

Where this conversion comes up

Gallons are used for gasoline, milk, paint and fish tanks in the US; liters for bottled drinks, engine size and fuel outside the US. For fuel economy, fish tanks and drums (a standard oil drum is 55 US gal = 208.2 L). Uses US gallons; for imperial gallons multiply by 4.546 instead.

Quick estimate

Multiply by 4 and subtract 5%: 10 gal ≈ 38 L, exact 37.85 L.

Common mistakes

• Dividing instead of multiplying. A liter is smaller than a gallon, so the number of liters must come out larger: 1 gallon = 3.78541 L.
• Using the imperial (UK) unit. This page uses US measures. An imperial gallon is 4.546 L (20% more than a US gallon), an imperial pint 568 ml and an imperial fluid ounce 28.41 ml.
• Rounding too early. Keep the full factor until the last step; rounding 3.79 to 4 first puts large values noticeably off.

Going the other way? Use the liters to gallons converter. Related volume converters: ml to oz, oz to ml, liters to quarts, quarts to liters, gallons to quarts, oz to cups.