UK Gallons to US Gallons Converter

How to convert UK Gallons to US Gallons

To convert UK Gallons to US Gallons, multiply the value in UK Gallons by 1.2009505. For example, 5 gal = 6.0047525 gal.

The UK Gallons-to-US Gallons conversion comes up often in everyday and professional contexts alike. With 1 gal equal to 1.2009505 gal, you can use the tool above for any value, or scan the table below for the most common UK Gallons amounts and their US Gallons equivalents.

Volume conversions are essential in the kitchen, in science, and in any situation involving liquids or capacity. They're also one of the trickiest areas because US and UK (imperial) measurements share names but differ in size.

Understanding UK Gallons and US Gallons

A US gallon (3.785 liters) is noticeably smaller than a UK gallon (4.546 liters) — about 20% less. The same applies to pints, quarts, and fluid ounces. Cups, tablespoons, and teaspoons are the backbone of recipe measurement, while liters and milliliters dominate scientific and most international contexts. This US/UK split is the single biggest source of error in volume conversion.

How accurate is this conversion?

Volume conversions here use the internationally accepted definitions: the US gallon is exactly 3.785411784 liters and the imperial gallon is exactly 4.54609 liters. Always confirm which system a recipe or specification uses before converting.

All conversion factors on ClearUnits are based on internationally recognised standards (the International System of Units, SI, and official definitions). Factors are reviewed for accuracy and the calculator uses full-precision values, rounding only the displayed result.

Quick reference: common UK Gallons to US Gallons values

The most frequently searched conversions are 1 UK Gallons = 1.2009505 US Gallons, 5 UK Gallons = 6.0047525 US Gallons, 10 UK Gallons = 12.009505 US Gallons, and 100 UK Gallons = 120.09505 US Gallons. The full table further down covers every common value, and the calculator handles any number you need in between.