How Many Gallons in a Barrel?

One barrel of crude oil contains 42 US gallons (159 liters). This is the standard unit used in the global oil industry. When you hear "oil is trading at $80 a barrel," thats 42 gallons. The number has nothing to do with modern logic, it dates back to the 1860s Pennsylvania oil boom.

🛢️ Oil Barrel Facts

🛢️ Why Exactly 42 Gallons?

In the 1860s, early Pennsylvania oil producers experimented with various container sizes. They settled on the 42-gallon barrel already in common use for shipping herring, wine and other goods. In August 1866, a group of oil producers formally agreed on 42 gallons as the standard to ensure fair trading. The number has stuck for over 160 years, even though crude oil hasnt actually been shipped in physical barrels since the early 1900s.

⛽ How Much Gasoline Comes From One Barrel of Oil?

One 42-gallon barrel of crude oil yields about 19 to 20 gallons of gasoline, plus roughly 12 gallons of diesel, 4 gallons of jet fuel, and various byproducts like lubricants, asphalt and petrochemicals. Interestingly, the total output actually exceeds 42 gallons, coming to about 45 gallons of finished products. This is called processing gain and happens because some refining processes add volume.

💰 What Does "Oil at $80 a Barrel" Actually Mean?

When news reports say oil is trading at a certain price per barrel, they mean the spot price for 42 US gallons of crude. At $80 per barrel, thats about $1.90 per gallon of crude. But crude oil needs to be refined, transported and taxed before it reaches your gas tank, which is why gasoline costs significantly more per gallon than the crude oil price would suggest. Refining alone adds about $0.50 to $0.80 per gallon.

🌍 Do All Countries Use the 42-Gallon Barrel?

The 42-gallon barrel is the global standard for pricing crude oil, even in metric countries. OPEC, the international oil cartel, quotes prices in US dollars per barrel. Some countries internally measure oil in metric tons or cubic meters, but for trading purposes everyone uses the 42-gallon barrel. One metric ton of crude oil equals roughly 7.33 barrels, though this varies slightly depending on the density of the specific crude.

🛢️ Oil Hasnt Been Shipped in Actual Barrels Since the Early 1900s

Despite the industry pricing everything "per barrel," crude oil hasnt been transported in physical 42-gallon wooden barrels for over a century. Modern oil moves through pipelines, tanker ships, rail cars and trucks. The barrel survives purely as an accounting unit. A single supertanker carries about 2 million barrels, the equivalent of roughly 84 million gallons. The wooden barrel that gave the unit its name is a relic of the 1860s Pennsylvania oil boom.