Question: how many litres are in a keg?
Answer: In the U.S. the terms half-barrel and quarter-barrel are derived from the U.S. beer barrel, legally defined as being equal to 31 U.S. gallons (this is not the same volume as some other units also known as barrels). A 15.5 U.S. gallon keg is also equal to: 12.7 Imperial gallons. 58.67 liters.