This page helps you to convert Imperial Gallons to litres and US gallons 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 Imperial Gallons to a litre and US Gallon! Simply enter your desired figure into the Imperial 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 US Gallon Converter.