Convert gallons to liters

U.S. Gallon

Definition
The U.S. liquid gallon (gal US) measures volume in the U.S. customary system. It’s defined as exactly 231 cubic inches, which converts to 3.785411784 L.

Origins
Derived from Old Northern French galon, the gallon first served wine and ale trade in medieval England. Over time, regional “wine” and “ale” gallons gave way to today’s standardized U.S. gallon.

Modern Use
In the United States, gallons commonly label large containers—milk jugs, ice-cream tubs, and household detergents—and fuel economy is expressed in miles per gallon. Despite global metrication, the U.S. retains this unit at the pump and on packaging.

Liter

Definition
A liter (L) is a metric volume unit equivalent to 1 dm³, 1 000 cm³, or 0.001 m³. Though not an SI base unit, it’s fully compatible and widely used.

Origins
From 1901 to 1964, a liter tied to the mass of one kilogram of pure water at maximum density. Variations in water properties led to a simpler definition: exactly one cubic decimeter.

Modern Use
Liters are the global standard for beverage bottles, food packaging, and fuel in most countries. Beyond liquids, liters describe capacities like backpack volume, car trunks, and appliance interiors.

U.S. Gallon → Liter Conversion Table

How to Convert

• 1 gal US = 3.785411784 L

• 1 L = 0.2641720524 gal US

Example

Convert 15 gal US to liters:

15 gal US × 3.785411784 L/gal US = 56.78117676 L