US Gallons to US Liquid Barrels (gal to bbl (US))

1 US gallon equals 0.03174603175 US liquid barrels (rounded).

1 US gallon = 0.03174603175 US liquid barrels

How to convert US gallons to US liquid barrels

To convert US gallons to US liquid barrels, multiply the number of US gallons by 0.03174603175. The factor is rounded to 10 significant digits. To go the other way, multiply US liquid barrels by 31.5.

US liquid barrels = US gallons × 0.03174603175

Example: 10 US gallons = 0.3174603175 US liquid barrels.

Pints, quarts, gallons and fluid ounces differ between the US and the UK. Units are labeled 'US' or 'imperial' to avoid confusion.

About these units

US Gallon (gal)

US customaryCurrent unit

Exactly 231 cubic inches or 3.785411784 liters (128 US fluid ounces). About 17% smaller than the imperial gallon.

The US gallon is a survivor of English wine trade. Around 1706, a statute in Queen Anne's reign fixed the wine gallon at exactly 231 cubic inches, settling confusion among the competing gallons for wine, ale and corn. British colonies in North America used that wine gallon, and in 1824 Britain replaced all its gallons with a new imperial one while the United States kept the old measure. It was adopted as the legal US standard in 1836 and is still defined as exactly 231 cubic inches, or 3.785411784 liters.

That makes the US gallon about 17 percent smaller than the imperial gallon, a difference that explains why American and British fuel-economy figures cannot be compared directly. Everyday uses are milk jugs, paint cans and gasoline pumps. One gallon divides evenly into four quarts, eight pints, sixteen cups and 128 fluid ounces. A gallon of water weighs a little over 8 pounds, an easy figure to remember when loading a car with water jugs.

1 US gallon = 3.785411784 liters (exactly).

Sources: Wikipedia: Gallon; NIST SP 811, Appendix B.8: conversion factors for volume

US Liquid Barrel (bbl (US))

US customaryTraditional unit (still used in some regions)

31.5 US gallons (119.24 L). The standard US barrel for liquids such as beer.

Most American fluid barrels are set at 31.5 US gallons, which works out to about 119 litres (119.24 L as used here). That is a half of the old 63 gallon wine hogshead, so the liquid barrel is a direct descendant of the English wine-gallon system rather than of any grain measure. Beer is the best known use, though the common US beer keg barrel is slightly smaller at 31 gallons, about 117 litres.

The English name came from French baril. Colonial and later American law treated the barrel as a trade unit for wine, beer, cider and spirits, but other liquids, from molasses to petroleum, were sold in containers of other sizes, so the phrase barrel never meant a single universal amount.

Confusion with its neighbours is common. It is roughly 3 percent larger than the dry barrel of 7,056 cubic inches, and well short of the 42 gallon barrel used for oil. The 63 gallon hogshead is exactly twice its size.

1 US liquid barrel = 119.2404712 liters (approximately).

Sources: Wikipedia: Barrel (unit); Wikipedia: Hogshead

Related conversions

See all volume units.