Gallon (US)

Definition: The US gallon is a unit of volume used primarily in the United States for measuring liquids. One US gallon equals exactly 3.785411784 liters or 128 US fluid ounces. The US gallon is different from the imperial gallon (used historically in the UK), which equals 4.54609 liters.

History/origin: The gallon has ancient origins, derived from the Roman "galleta" or "galletum," meaning a jug or pail. The US gallon was defined in 1832 as the volume of 8.33 pounds of water at maximum density. The modern definition was established in 1959 as exactly 231 cubic inches or 3.785411784 liters.

Current use: The US gallon is primarily used in the United States for measuring gasoline/fuel, milk, water, and other liquids. It remains the standard unit in the US despite the global adoption of the metric system in most scientific and industrial applications. Gas stations, grocery stores, and most consumer products in the US use gallons as the primary unit of liquid volume.

Liter

Definition: The liter (symbol: L or l) is a metric unit of volume equal to one cubic decimeter (1 dm³). One liter equals approximately 0.264172 US gallons. The liter is part of the International System of Units (SI) and is the standard unit for measuring liquid volumes worldwide.

History/origin: The liter was first defined in 1795 during the French Revolution as one cubic decimeter. The name comes from the French "litron," an old measure of capacity. Since 1964, the liter has been defined as exactly one cubic decimeter (1,000 cubic centimeters).

Current use: The liter is used worldwide for measuring liquid volumes, including beverages, fuel, cooking liquids, and most liquid measurements in countries using the metric system. It's the standard unit for larger liquid quantities globally, except in the United States where gallons remain prevalent.

Gallon to Liter Conversion Table

How to Convert Gallon to Liter