Gallon
| gallon | |
|---|---|
A one-US-gallon gas can showing "U.S. Gallon" marking (for American use), imperial gallons (for British use), and litres (for Canadian use) | |
| General information | |
| Unit of | Volume |
| Symbol | gal |
| Conversions (imperial) | |
| 1 imp gal in ... | ... is equal to ... |
| Non-SI units accepted for use with SI | 4.54609 L |
| US customary units | ≈ 1.200950 US gal |
| US customary units | ≈ 277.4194 in3 |
| Conversions (US) | |
| 1 US gal in ... | ... is equal to ... |
| Non-SI units | 3.785411784 L |
| Imperial units | ≈ 0.8326742 imp gal |
| Imperial units | 231 in3 |
The gallon is a unit of volume in British imperial units and United States customary units.
The imperial gallon (imp gal) is defined as 4.54609 litres, and is or was used in the United Kingdom and its former colonies, including Ireland, Canada, Australia, New Zealand, India, South Africa, Malaysia and some Caribbean countries, while the US gallon (US gal) is defined as 231 cubic inches (3.785411784 L), and is used in the United States and some Latin American and Caribbean countries.
There are four gills in a pint, two pints in a quart, and four quarts (quarter gallons) in a gallon, with the imperial gill being divided into five imperial fluid ounces and the US gill being divided into four US fluid ounces: this, and a slight difference in the sizes of the imperial fluid ounce and the US fluid ounce, give different sizes for the imperial gallon and US gallon.
The IEEE standard symbol for both the imperial and US gallons is gal, not to be confused with the gal (symbol: Gal), a CGS unit of acceleration.