Gallon, << GAL uhn, >> is a unit of volume and capacity used for liquids. It is part of the inch-pound system of measurement customarily used in the United States. A gallon is the amount of liquid that will fill a container of exactly 231 cubic inches. One gallon equals 3.785 liters. A fourth of a gallon is a quart. A half-quart is called a pint.
The imperial gallon is sometimes used in the United Kingdom. However, it has been largely replaced by metric units of measurement. The imperial gallon contains 277.420 cubic inches of liquid and is equal to 4.546 liters.
