Convert Gallon (US) (gal (US)) to Fluid Ounce (UK) (fl oz (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.
Fluid Ounce (UK) (fl oz (UK))
A UK fluid ounce equals 28.4130625 mL, slightly larger than the US fluid ounce. It forms part of the imperial system used in cooking, beverage preparation, and older pharmaceutical formulations. Imperial fluid ounces were historically derived from the UK gallon (1/160 of a gallon), distinguishing them from US units derived from a different gallon. Though metric units dominate in the UK today, fluid ounces still appear in bartending, antique recipes, and product packaging that caters to traditional preferences or legacy export markets.