What Is Barrel (Us)?
A Barrel (US) is a unit used to measure volume, usually for large amounts of liquid. Today it is best known for measuring crude oil and oil products. One standard US oil barrel holds 42 US gallons of liquid.
Definition
When people say Barrel (US) in the oil business, they almost always mean the standard US oil barrel.
- 1 Barrel (US, oil) = 42 US gallons
- 1 Barrel (US, oil) is about 159 liters (more exactly about 158.99 liters)
- 1 Barrel (US, oil) is about 5.61 cubic feet
In other industries inside the United States, the word barrel can mean other sizes. For example, a beer barrel is often 31 US gallons. Because of this, when people talk about crude oil or fuel, Barrel (US) almost always means the 42 gallon oil barrel.
History / Origin
The idea of a barrel as a measure comes from wooden barrels used to store and move goods like wine, beer, and fish in old times.
In the 1800s, when people first began to pump and sell crude oil in the United States, they did not have a special container for it. They used many types of wooden barrels that were already common. Sizes were not the same, which caused confusion and unfair deals.
To fix this, oil sellers and buyers agreed on a single standard size. In the 1860s in Pennsylvania, the oil industry chose a barrel of 42 US gallons as the standard for crude oil. This size became widely accepted and later was written into laws and rules. Over time, the 42 gallon oil barrel became the normal unit for oil trade around the world.
Symbol & Abbreviation
Several short forms are used for the Barrel (US) in writing:
- bbl is the most common symbol for one Barrel (US) of oil
- bbls can be used for more than one barrel
- US bbl may be used when writers want to make clear it is the US oil barrel
You may also see barrel in time based units, such as:
- bbl/d or bbl per day for barrels produced or used in one day
- MMbbl for one million barrels
- Mbbl for one thousand barrels, though sometimes Mbbl is also used for one million barrels, so readers must check the meaning in context
Current Use Around the World
The Barrel (US) is still a very important unit in the global oil and gas industry.
- Crude oil production is often written in barrels per day (bbl/d)
- Oil reserves of a country or company are listed in millions or billions of barrels
- Prices in news reports usually say US dollars per barrel for crude oil or some fuels
Even though most countries now use the metric system, the US oil barrel stays the main trade unit for crude oil and many oil products worldwide.
Inside the United States, other types of barrels are used for different products, for example beer and some food items, but these may have different gallon values. In science and engineering, people more often use liters or cubic meters, but they can easily convert to barrels when needed for trade or reports.
Example Conversions
Below are simple example conversions for the standard US oil barrel of 42 US gallons.
From Barrels (US) to US Gallons
- 1 bbl = 42 US gal
- 5 bbl = 5 × 42 = 210 US gal
- 10 bbl = 10 × 42 = 420 US gal
From Barrels (US) to Liters
Use 1 bbl ≈ 158.99 L (about 159 L).
- 1 bbl ≈ 159 L
- 2 bbl ≈ 2 × 159 = 318 L
- 10 bbl ≈ 10 × 159 = 1,590 L
From Barrels (US) to Cubic Meters
Use 1 bbl ≈ 0.15899 m³ (about 0.159 m³).
- 1 bbl ≈ 0.159 m³
- 50 bbl ≈ 50 × 0.159 = 7.95 m³
- 100 bbl ≈ 100 × 0.159 = 15.9 m³
From Liters to Barrels (US)
Use 1 bbl ≈ 159 L, so:
- 159 L ≈ 1 bbl
- 1,000 L ≈ 1,000 ÷ 159 ≈ 6.29 bbl
- 10,000 L ≈ 10,000 ÷ 159 ≈ 62.9 bbl
Related Units
Units closely related to the Barrel (US) include:
- US gallon (gal) main unit that defines the US oil barrel, since 1 bbl = 42 US gal
- Liter (L) common metric unit for liquid volume used in daily life and science
- Cubic meter (m³) main metric unit for large volumes in industry and engineering
- Cubic foot (ft³) another volume unit used in the US, often for natural gas
- Drum a common steel container, often 55 US gallons, different from the 42 gallon oil barrel
- Other US barrels such as beer barrel (often 31 US gallons) and some food barrels with other gallon values
FAQs
How many gallons are in one Barrel (US)?
One standard US oil barrel holds exactly 42 US gallons of liquid.
How many liters are in one Barrel (US)?
One Barrel (US) of oil is about 159 liters. The more exact value is about 158.99 liters.
Why is an oil barrel 42 gallons?
In the 1800s, early US oil producers used many barrel sizes. They later agreed to use a single size for fairness in trade. They chose the 42 gallon barrel, and this size became the standard.
Is a Barrel (US) the same as a 55 gallon drum?
No. A 55 gallon drum holds 55 US gallons, which is more than a 42 gallon oil barrel. People sometimes mix the terms in daily talk, but they are different sizes.
Do all barrels in the US hold 42 gallons?
No. The 42 gallon size is standard for crude oil. Other products can use other barrel sizes, such as 31 gallons for some beer barrels. That is why context matters.
Is the Barrel (US) used outside the United States?
Yes. The oil industry in many countries uses the US barrel when talking about production, trade, and prices. Even in metric system countries, oil is still often counted in barrels.
What does barrels per day mean?
Barrels per day (bbl/d) tells how many barrels of oil are produced, sold, or used in one day. It is a common way to compare oil production between fields, companies, or countries.
