Convert Gallon (US) (gal (US)) to Gallon (UK) (gal (UK)) instantly.
About these units
Gallon (US) (gal (US))
The US gallon is defined as exactly 231 cubic inches, or 3.785411784 liters. It is widely used in American commerce for gasoline, milk, water, and other household liquids. Its historical roots lie in old English wine and ale gallons, whose varying definitions ultimately led to divergent US and UK systems. Today, the US gallon remains deeply embedded in American culture, especially in automotive contexts—fuel economy ratings such as "miles per gallon" (MPG) illustrate its everyday relevance. Despite the global shift toward metric volume units, the US gallon persists due to familiarity and regulatory inertia. It remains an iconic unit, symbolizing uniquely American measurement traditions.
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.