I know what you're probably thinking, why haven't you used google? Well the reason is this 1 US gallon = 3.785ltr and 1 imperial gallon = 4.546ltr. Obviously a sizeable difference. I'm looking to buy a glass carboy and I see a lot of you guys talk about 5gallon carboys so I'm wondering what size that will be in litres. It will also help me down the line when I'm reading recipies etc. Thanks in advance