Convert Gallons to Imperial Gallons

Convert Gallons (gal) to Imperial Gallons (UK gal) instantly and accurately.

Conversion Formula

UK gal = gal × 0.8326741846

About Gallons

A US gallon (gal) = 4 quarts = 128 fl oz ≈ 3.785 L. Gasoline, milk, water, paint, and pesticides are sold by the gallon in the US. About 20% smaller than the UK imperial gallon (4.546 L) - a critical difference when comparing fuel economy across the Atlantic. 1 US gal = 3.785 L = 4 qt = 128 fl oz.

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.

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