Barrel (bbl) definition

A barrel, abbreviated bbl, is the standard unit of volume for crude oil and equals 42 US gallons, or about 159 litres. Crude oil prices are almost always quoted per barrel, so the unit underpins how the market measures and values oil.

When crude trades at a given price, that figure refers to one barrel, so a quote of 80.00 means 80 US dollars for 42 US gallons. Production and storage volumes are also expressed in barrels, often as barrels per day for output and millions of barrels for inventories.

Keep in mind that a barrel measures volume, not weight, so it should not be confused with tonnes, which some other commodities use. The oil barrel of 42 US gallons also differs from the 55 US gallon steel drum often pictured alongside it.

Barrel (bbl) Example

You read that a position covers 1,000 barrels of crude. Since one barrel equals 42 US gallons, that position represents 42,000 US gallons of oil.

1 barrel = 42 US gallons (about 159 litres)