Oil Barrels

An oil barrel (abbreviated as bbl) is a unit of volume whose definition has not been universally standardized. In the United States, an oil barrel is defined as 42 US gallons, which is about 159 liters or 35 imperial gallons. In Canada, oil companies measure oil in cubic meters but convert to barrels on export, since most of Canada's oil production is exported to the US. The nominal conversion factor is 1 cubic meter = 6.2898 oil barrels, but conversion is generally done by custody transfer meters on the border since the exact conversion factor depends on oil density and temperature.
Oil companies that are listed on American stock exchanges typically report their production in terms of volume and use the units of bbl, Mbbl (one thousand barrels), or MMbbl (one million barrels). Outside the United States, volumes of oil are usually reported in cubic meters (m3) instead of oil barrels. Cubic meter is the basic volume unit in the International System.