UK Barrels
A UK barrel is 36 imperial gallons (not to be confused with American gallons), about 163.659 liters or 0.163659 cubic meters. It is based on the traditional wine barrel used in the United Kingdom.
US Liquid Barrels
A US liquid barrel is a volume unit used in the United States to measure the volume of liquids. One US liquid barrel is equivalent to 31.5 US gallons or about 119.24 liters.
To convert this unit please visit: US liquid barrel conversions.
Note that there are many types of barrel so be sure to choose the correct one for your needs.