Hectoliter is a metric unit of volume equal to 100 liters. It is the major unit of volume used in the brewing industry worldwide. Even in the two countries that have resisted the metric system, the United States and the United Kingdom, the hectoliter is slowly replacing the US beer barrel (117.35 liters) and the UK beer barrel (163.66 liters) as units of beer measurement. Measures equaling “one barrel” differ widely from country to country and between different industries. The metric hectoliter avoids those differences and makes scientific calculation easier. The abbreviation for the hectoliter is “hl.”