The oil price per barrel is the headline number for the world's most-traded commodity, but "the price of oil" is really several prices. Brent, WTI, Dubai and the OPEC Reference Basket can differ by several dollars a barrel on the same day, and each is quoted in U.S. dollars per barrel of 42 U.S. gallons. This page puts the two main benchmarks on live charts, explains what a barrel is and why oil is priced this way, and shows how to compare quotes from different sources.
What a Barrel of Oil Is
A barrel is a unit of volume, not weight: 42 U.S. gallons, equal to about 159 litres or 35 imperial gallons. The size dates from 19th-century Pennsylvania, where oil was shipped in wooden whiskey barrels and the 42-gallon cask became the trade standard in 1866. No physical barrels are involved in modern trade — crude moves by pipeline and tanker in cargoes of hundreds of thousands of barrels — but the unit survived as the pricing convention. A very large crude carrier holds roughly two million barrels; global consumption runs to around 100 million barrels a day.
Because crude oils have different densities, a barrel of light crude weighs less than a barrel of heavy crude. Roughly 7.3 barrels make one metric tonne for a typical grade, which matters when comparing per-barrel quotes with markets, such as fuel oil, that price per tonne. For the density scale itself, see API gravity.
Why Oil Is Priced in Dollars per Barrel
Virtually all internationally traded crude is quoted in U.S. dollars per barrel. The dollar convention grew out of the post-war dominance of American oil companies and the dollar's role as the reserve currency, and it persists because it gives producers, refiners and traders a single unit of account. One practical consequence is that the oil price per barrel and the dollar tend to move inversely: when the dollar strengthens, oil becomes more expensive for buyers in other currencies, which weighs on demand and often on the dollar price.
Brent vs WTI vs Dubai vs OPEC Basket
The three global benchmarks and the OPEC basket answer slightly different questions:
- Brent — light, sweet North Sea crude; the reference for roughly two-thirds of internationally traded oil and the price most often meant by "the world oil price." The live figure is the front-month ICE Brent futures contract.
- WTI — West Texas Intermediate, the U.S. benchmark delivered at Cushing, Oklahoma and traded on NYMEX. American news outlets usually quote WTI when they say "oil."
- Dubai — the medium-sour Middle East benchmark that prices most crude sold into Asia; usually a few dollars below Brent because of its higher sulphur content.
- OPEC Reference Basket — a weighted average of the member countries' main export grades, published daily by the OPEC Secretariat and used as the cartel's own yardstick.
Brent usually trades at a premium to WTI; the gap, known as the Brent/WTI spread, reflects shipping costs, U.S. export capacity and regional inventories. Quality differences — density and sulphur — explain most of the remaining gaps between grades, as covered in sweet vs sour crude.
What Moves the Oil Price per Barrel
Day to day, the price per barrel responds to the balance between supply and demand and to expectations about that balance. On the supply side the biggest levers are OPEC+ production policy, U.S. shale output, and disruptions to flows through chokepoints such as the Strait of Hormuz. On the demand side, economic growth, refinery runs and seasonal driving and heating patterns dominate. Weekly inventory data from the EIA Petroleum Status Report provide the most frequent hard evidence of whether the market is over- or under-supplied, and the shape of the futures curve — contango or backwardation — tells you how tight prompt barrels are.
From the Barrel to the Pump
Crude is only part of the cost of the products people buy. Refiners convert each barrel into gasoline, diesel, jet fuel and other products, and the margin they earn — the crack spread — rises and falls independently of crude. Taxes, distribution and retail margins make up the rest of a pump price, which is why fuel prices move more slowly, and by a smaller percentage, than the oil price per barrel. A rough rule of thumb for U.S. gasoline is that every $1 change in the crude price per barrel is worth about 2.4 cents per gallon, all else being equal.
Reading Today's Price Correctly
When comparing today's oil price per barrel across sources, check three things: which benchmark is being quoted, whether it is the futures contract or the physical spot assessment, and whether the feed is delayed. A headline saying oil "topped $100" almost always refers to front-month Brent or WTI futures. For the historical context — where $100 sits relative to the 2008 peak of $147, the 2020 collapse and the 2026 Hormuz spike — see the Brent price history. For a full-screen real-time chart, use the live Brent crude price page.
Oil Price per Barrel FAQ
How many litres are in a barrel of oil?
About 158.99 litres — 42 U.S. gallons.
Which oil price should I follow?
Brent for the global market and anything outside North America; WTI for U.S. producers, refiners and pump prices. Most of the time they move together, so the choice matters less than being consistent.
Is the price per barrel the same as the price consumers pay?
No. Consumers buy refined products, whose prices add refining margins, taxes and distribution costs on top of the crude price.
Why are oil prices sometimes quoted per tonne?
Refined products such as fuel oil and some physical crude trades are priced by weight. Converting requires the grade's density; roughly 7.3 barrels equal one tonne for a typical medium crude.
Continue Reading
- Brent Crude Price Today — the live Brent dashboard
- Live Brent Crude Price — full-screen real-time chart
- Brent/WTI Spread — why the two benchmarks diverge
- OPEC Reference Basket — the cartel's own price measure
- How to Read Oil Charts — interpreting price charts