Barrels to litres
A barrel of oil (bbl) is 42 US gallons, exactly 158.987 litres. Nobody ships oil in physical barrels any more, but the unit stayed in the trade: cargo quantities, prices and market reports are all in barrels, while the ship measures the same oil in cubic metres and pays for bunkers in tonnes.
Quick try:
A barrel here is the barrel of oil: 42 US gallons, about 159 litres. The US gallon and the imperial gallon are two different units.
Barrels converted
| bbl | l | m³ | gal US |
|---|---|---|---|
| 1 | 158.9873 | 0.1589873 | 42 |
| 10 | 1,589.873 | 1.589873 | 420 |
| 100 | 15,898.73 | 15.89873 | 4,200 |
| 1,000 | 158,987.3 | 158.9873 | 42,000 |
| 5,000 | 794,936.5 | 794.9365 | 210,000 |
| 10,000 | 1,589,873 | 1,589.873 | 420,000 |
Values computed from the exact definitions of the units (NIST SP 811 and the international agreements), rounded to 7 significant digits. The first column is barrels of oil.
Barrels, gallons and tonnes
The US gallon is 3.785 litres, the imperial gallon 4.546 litres, so a British gallon is one fifth larger than an American one. The barrel of oil is built on the American gallon: 42 of them. Whenever a figure is written just "gallons", find out whose gallon it is before you order anything.
Barrels and tonnes cannot be converted without the density of the cargo. For a typical crude of about 0.85 t/m3 you get roughly 7.3 barrels to the tonne, but a light crude gives more and a heavy one fewer. That is why a bunker delivery note carries a density at 15 °C: without it, volume tells you nothing about the quantity you actually received.
Frequent questions
How many litres are in a barrel of oil?
About 159 litres, exactly 158.987 l, because a barrel is defined as 42 US gallons.
How many barrels are in a tonne?
It depends on the density. For a typical crude it is about 7.3 barrels per tonne; for a light product more, for a heavy fuel oil fewer. Always take the density from the cargo or bunker documents.
Is a US gallon the same as an imperial gallon?
No. A US gallon is 3.785 l and an imperial gallon is 4.546 l, a difference of about 20%. Lubricants and stores ordered in the wrong gallon is a mistake that shows up on delivery.
Why are bunkers bought in tonnes and cargo sold in barrels?
Because a tonne of fuel gives the same energy whatever its temperature, while volume swells and shrinks with heat. Cargo trading kept the barrel out of habit and history, and the ship reconciles the two with density and temperature corrections.