Convert Imperial Gallons to Fluid Ounces

Convert Imperial Gallons (UK gal) to Fluid Ounces (fl oz) instantly and accurately.

Conversion Formula

fl oz = UK gal × 153.7215905

About Imperial Gallons

A US imperial gallon (UK gal) = exactly 8 imperial pints or 10 lb of pure water at 62°F ≈ 4.546 L - about 20% larger than the US liquid gallon (3.785 L). The weight-based definition made it verifiable with simple scales. Still the legal fuel measure in the Cayman Islands and other British Overseas Territories. UK mpg ratings use imperial gallons: 50 UK mpg ≈ 42 US mpg. 1 UK gal ≈ 4.546 L.

About Fluid Ounces

A fluid ounce (fl oz) is a US customary volume unit equal to 1/8 of a cup or 1/128 of a gallon - approximately 29.574 mL. Despite sharing a name with the weight unit 'ounce', fluid ounces measure volume, not mass. In the US, beverages are universally labeled in fluid ounces: a standard can of soda is 12 fl oz, a standard wine pour is 5 fl oz, and a shot of spirits is 1.5 fl oz. Note that the UK imperial fluid ounce (28.413 mL) differs slightly from the US fluid ounce (29.574 mL) - a common source of confusion in international recipes and product comparisons.

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