Convert Barrel (Oil) (bbl (oil)) to Gallon (UK) (gal (UK)) instantly.
About these units
Barrel (Oil) (bbl (oil))
An oil barrel is defined as 42 US gallons, or 158.987 liters, and is a fundamental unit in the petroleum industry. This peculiar size traces back to the early Pennsylvania oil fields, where producers standardized whiskey barrels and modified wooden casks for oil transport. The need for consistent trade volumes cemented the 42-gallon barrel as the industry norm. Today, global oil production, pricing, and consumption are expressed in barrels—from daily OPEC reports to energy market forecasts. Even though oil is no longer physically shipped in barrels, the unit remains deeply embedded in international energy economics.
Gallon (UK) (gal (UK))
The UK gallon, defined as 4.54609 liters, is larger than the US gallon by nearly 20%. It originated from the British desire to standardize wine and ale measures, leading to a uniform definition during the 19th century. Today, the UK gallon appears in older recipes, fuel consumption discussions, and British Commonwealth trade documents. Although the UK now uses liters for petrol and milk, the gallon remains culturally familiar, especially in automotive contexts such as miles per gallon (MPG), where both imperial and US definitions cause frequent confusion. The UK gallon's legacy persists through its continued use in some Commonwealth nations and specialized industries where imperial measures remain customary.