I am glad someone mentioned the difference because depending on where you live in the world it will vary how many liters to a gallon there are.
I live in the UK and my first answer was to tell you there are 4.5 liters to a gallon. If you live in the US however it is a lot less at 3.79 liters to a gallon.
You need to be aware of the two main standards that exist. which can cause confusion:
The Imperial gallon - used in the UK
and
The Standard gallon used in the USA.
The UK gallon has 4.55 litres and the US gallon has 3.79 litres!
as you will likely get more people with the correct answer. Also it will benefit others if they also wish to look for why there was a need for a dry and liquid measurement of a gallon.
...There are actually three different gallons that I know of.
Imperial (British) 4.546l
US (dry gallon) 4.4l
US(liquid gallon) 3.791l
If I can hijack this question, does anyone know why there was a need for a US dry gallon and also a liquid gallon?
...