This page will help you convert US Gallons to litres and imperial gallons easily, quickly and completely for free. You can either use the gallon conversion calculator below or check out the table we have created which displays some of the most common US Gallon conversions. Use this tool to easily work out how many US Gallons to a litre and Imperial Gallon! Simply enter your desired figure into the US Gallon field in either of the calculators below and the conversion will occur automatically. Check out our other converters and calculators such as our MPG Calculator, Litre Converter and Imperial Gallon Converter.