Oil prices slump, hike, and fluctuate throughout the year. Listening to the news closely, they usually use a unit of measurement called “barrel.” Oenophiles might associate oil barrels with oak wine barrels or casks. Kegs might come to mind for beer lovers. But are they the same as the oil barrel? And how big is a barrel of oil? The infographic above visualizes how big a barrel of oil is and what a barrel of oil can make.
How Big Is a Barrel of Oil?
Straight to the answer, a barrel of oil is 42 US gallons. For those outside of the US, one gallon is 3.785411784 L, defined as 231 cubic inches. This makes a barrel of oil equivalent to 158.987294928 L or conventionally 159 L. For those who use imperial gallon, i.e., those who are in UK, Ireland, Canada, Australia and some Caribbean countries, a barrel of oil equals 35 imperial gallons. In terms of weight, a barrel of oil weights approximately 136 kg or 300 pounds.
Nearly 100 million barrels of oil is moved every day. Surprisingly—or not so surprisingly—oil is not shipped in actual barrels today. When oil spills occur at ocean, it is not a barrel that spills oil. It is a wrecked tanker or a barge that spills oil. Similarly, when oil leaks occur on land, it is a damaged pipeline or a truck that spills oil, not a barrel. Barges, tankers, pipelines, trucks and railroads carry oil, just like other hazardous material. No one indeed orders a barrel of oil—the largest of these vessels is 415 m, carrying up to 550,000 DWT (Dead Weight Tonnage).
If oil is not stored in barrels, then why is oil unit barrel? To answer this question, let’s take a look at oil’s history, back to the mid 19th Century.
Why Is Oil Measurement Unit Barrel?
In 1859, Edwin Drake discovered oil in Pennsylvania, which led to the first oil boom in the US in coming decades. In the primitive oil production process, there was no pipeline or tank to store oil—they used wooden barrels that were standard containers then. Barrels were a lot more common in people’s life in those days. People used barrels to transport everything: salmon, herring, molasses, soaps, wine, and whale oil. The watertight barrels were the perfect container for the new runny essential.
Since there was no standard procedure, barrels in different sizes were in use in the oil field. Oil producers used 42-US-gallon barrels, 159-litre tierce, 40-US-gallon whisky barrels, and 45-US-gallon barrels. Among them, 40-US-gallon barrels were most easily available hence most common in the oil field. Today’s standard oil barrel—42 US gallons—was widely used in West Virginia and Pennsylvania.
As oil production and trade increased, shipping oil in different containers caused problems. In 1866, an Oil City newspaper, the Weekly Register reported “the oil producers have issued the following circular:”
An allowance of two gallons will be made on the gauge of each and every 40 gallons in favor of the buyer.
This announcement promoted the 42-US-gallon barrels among oil producers. In 1872, the Petroleum Producers Association finally adopted this procedure. In 1882, the U.S. Geological Survey and the U.S. Bureau of Mines officially adopted the 42-US-gallon barrel as the standard.
It is understandable this measurement became universal because the US has been the leading oil producing countries. Nevertheless, some countries especially former Soviet Union may measure oil in terms of weight and express the weight in metric tonnes.
What Can We Make out of One Barrel of Oil?
Now that we know a bit about a barrel of oil, let’s find out what a barrel of oil can produce. The 42-US-gallon 136-kg oil can surprisingly yield a large number of useful products. Breaking down the components, 50 – 97% of the barrel is hydrocarbons, 6 -10% organic compounds, and less than 1% metal.
Chevron, a multinational oil and gas corporation, shares interesting insights on their web page, “what’s in a barrel of oil?” According to them, one barrel of oil can produce:
- Enough liquefied gases (such as propane) to fill 12 small (14.1 ounce) cylinders for home, camping or workshop use.
- Enough gasoline to drive a medium-sized car (17 miles per gallon) over 280 miles.
- Asphalt to make about one gallon of tar for patching roofs or streets.
- Lubricants to make about a quart of motor oil.
- Enough distillate fuel to drive a large truck (five miles per gallon) for almost 40 miles. If jet fuel fraction is included, that same truck can run nearly 50 miles.
- Nearly 70 kilowatt hours of electricity at a power plant generated by residual fuel.
- About four pounds of charcoal briquettes.
- Wax for 170 birthday candles or 27 wax crayons.
This means a barrel of oil can provide a 14.1-ounce propane gas cylinder to 12 homes. We can drive Chevrolet Silverado 1500 (17 MPG) from Long Island NY to Washington D.C. (280 miles). And we can celebrate two 85-year-old grannies’ birthdays!
Even after this, enough petrochemicals are still in the same barrel for one of the following products:
- 39 polyester shirts
- 750 pocket combs
- 540 toothbrushes
- 65 plastic dustpans
- 23 hula hoops
- 65 plastic drinking cups
- 195 one-cup measuring cups
- 11 plastic telephone housings
- 135 four-inch rubber balls.
Other than these, lighter materials in a barrel can produce a quart of pain thinners or a quart of dry-cleaning solvents. Moreover, materials still left in the barrel can produce by-products such as medicinal oils, still gas, road oil and plant condensates.
Proportion of Each Product in One Barrel of Oil
Now, let’s see the barrel from a different angle. In 2020, the US consumed 18.1 million barrels of oil per day. The oil produced various petroleum products that we use in our daily lives. Then how much oil went to what product? Breaking down a barrel of oil into usage, each product takes up the following proportion in the barrel according to EIA data.
- 44.3% − Finished motor gasoline
- 20.8% − Distillate fuel oil (diesel fuel and heating oil)
- 17.6% − Hydrocarbon gas liquids (HGLs)
- 5.9% − Kerosene-type jet fuel
- 3.4% − Still gas
- 1.9% − Asphalt and road oil
- 1.6% − Petrochemical feedstocks
- 1.4% − Petroleum coke
- 1.2% − Residual fuel oil
- 0.8% − Miscellaneous products and other liquids
- 0.6% − Lubricants
- 0.2% − Special napthas
- 0.1% − Aviation gasoline
- >0.01% − Kerosene
- >0.005% − Waxes
The Final Words: A Barrel of Oil
Petroleum is versatile and creates a wide range of useful products from motor gasoline to clothes. Only one barrel of oil can make our lives more convenient, allowing us to drive, make our home warm, enjoy barbeque, and many others. Close to half of today’s oil production transforms into finished motor gasoline, and mostly it is used as fuel for transportation.
However, the future of petroleum may not be so bright. In fact, road transport accounted for 12% of global greenhouse gas emissions. Being aware of its environmental impact, the transport industry has been increasingly moving on from petroleum in recent years by introducing electric vehicles and alternative fuels.
Moreover, oil supply might be depleted in coming decades. Oil is extremely useful; it has helped human development since its discovery. However, it is a non-renewable resource. If we continue consuming oil at the same rate as today, then we might run out of oil in 48.7 years.