Oil Price to Gas Price Calculator

Type a Brent crude oil price below. The calculator estimates what US drivers would pay at the pump, and shows what makes up a gallon: the oil itself, the cost to refine it, fuel taxes, and getting it to your local station. Use it to see how an Iran oil shock or a Strait of Hormuz disruption could hit your gas bill.

Where the pump price comes from

A barrel of oil holds 42 gallons. So if oil costs $84 a barrel and that was the only cost, gas would be $2.00 a gallon. The pump price is higher because three other things get added on top:

• Refining. Refineries turn oil into gasoline. That work adds about 40 to 70 cents per gallon, depending on demand and whether refineries are running smoothly.
• Taxes. The federal government takes 18.4 cents per gallon. Each state adds its own tax on top. Alaska is around 9 cents, California is over 60 cents, and the US average is about 32 cents. Federal plus state usually adds up to around 50 cents per gallon.
• Getting it to the pump. Pipelines, trucks, terminals, and the gas station itself need to make money. That adds another 25 to 40 cents per gallon on a normal day.

Add them all up and the formula is: pump_price = (oil_price / 42) + refining + taxes + station_markup. That is what the calculator above does.

Why gas prices take a few weeks to catch up

When oil prices jump overnight, the gas station does not change its sign the next morning. Stations are still selling gasoline they bought weeks ago, so a new oil price takes a while to show up at the pump. A rough rule: a $10 per barrel jump in oil that sticks around adds about 25 to 30 cents per gallon at the pump within a month. Brief spikes that fade fast often do not fully reach you.

What Iran tensions could do to gas prices

Iran sits right next to the Strait of Hormuz, a narrow waterway that about 20% of the world's seaborne oil passes through (plus about a quarter of the global liquefied natural gas trade). The oil market watches this all the time. When the news sounds warlike, oil prices go up. Peace news brings them back down.

You can see today's IranPeaceDeal probability on the homepage, and how it has tracked Brent and US gasoline futures on the chart there.

To try a scenario, type the oil price the news would suggest and watch the pump price change. A short Hormuz scare that pushes oil $25 to $40 a barrel higher has historically added about 60 cents to a dollar per gallon at the pump over a few weeks. A full closure could push oil into the $130 to $200 range, which would mean US gas prices we have not seen since 2008 and 2022.

What this calculator gets wrong

• This is rough math, not a refiner's pricing model. When oil prices get really high or really low, the real-world math gets shakier than this simple version.
• WTI (the US oil benchmark) usually trades a few dollars below Brent. For a US-only shock, subtract about $3 to $5 from your input.
• The calculator only estimates regular gasoline. Diesel, jet fuel, and California's special blend all follow different rules.
• State prices can be more than a dollar per gallon away from the US average. If you want a state-specific number, adjust the tax field.

For how we estimate the daily Iran peace probability that drives this site, see methodology.