Gallon

The gallon (abbreviation: gal) is a non-SI measurement unit of volume used in the U.S. customary and the Imperial systems of measurement. Historically it has had many different definitions but, as of 2010, there are only three definitions in current use. These are the U.S. liquid gallon and the U.S. dry gallon which are used in the United States and the Imperial gallon which is in unofficial use within the United Kingdom and Ireland and in semi-official use within Canada. The gallon, be it the U.S. or Imperial gallon, is sometimes used in other English-speaking countries as well.

Definitions and divisions

 * The U.S. liquid gallon is equal to 3.785412 litres which is equivalent to 231 cubic inches. It is divided into:


 * 4 quarts (abbreviation: qt) or
 * 8 pints (abbreviation: pt) or
 * 32 gills (abbreviation: gi) or
 * 128 fluid ounces (abbreviation: fl oz)


 * The U.S. dry gallon is equal to 4.404884 litres which is equivalent to 268.8025 cubic inches. It is divided into:


 * 4 quarts (abbreviation: dry qt)
 * 8 pints (abbreviation: dry pt)


 * The Imperial gallon is 20 % larger than the U.S. liquid gallon and is equal to 4.546092 litres which is equivalent to 277.4196 cubic inches. It is divided into:


 * 4 quarts (liquid or dry) or
 * 8 pints (liquid or dry) or
 * 32 gills (liquid or dry) or
 * 160 fluid ounces (liquid only) which about 4% smaller than the fluid ounces in a U.S. gallon

Countries using the U.S. liquid gallon
As of 2005, the U.S. liquid gallon continued to be used as a unit of measure for fuel in Colombia, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Liberia, Nicaragua, Panama, Peru, and the United States.

Countries using the Imperial gallon
As of 2000, the Imperial gallon ceased to be a legal unit of measure within the United Kingdom for economic, health, safety or administrative purposes. However, as noted in the introduction (see above), the Imperial gallon is still in unofficial use within the United Kingdom and Ireland and in semi-official use within Canada.