Sky-high oil prices are causing a real headache for airlines and leading to higher ticket prices.

Since the Iran war began in late February, the price of Brent crude is up 41%. As of Friday, it's about $107 a barrel.

Jet fuel prices have been rising faster, too. They are typically airlines' biggest expenditure after labor. And while most European airlines use financial derivatives to hedge against fuel costs, US carriers do not.

Airlines' first-quarter earnings offered some insight into how much fuel costs are rising and how bosses plan to address it.

While fuel costs have increased across the board, it looks like there will be more dramatic jumps in the next quarter's earnings.

Here's what the four biggest airlines said about rising fuel costs.

Delta Air Lines

Delta Air Lines' fuel expenses were up $332 million in the first quarter, compared to the same period last year.

While costs have risen, Delta may be better placed than its rivals to contend with the fuel shock because it owns an oil refinery in Pennsylvania.

Chief Operating Officer Dan Janki said this is expected to help save $300 million in the next quarter, based on current prices.

Also during the earnings call, CEO Ed Bastian told investors how Delta plans to address higher fuel costs.

Bastian said the airline is "meaningfully" reducing capacity, and is aiming to "recapture higher fuel prices," or make up for the extra costs.

"Our customer base is showing greater resilience to macro and geopolitical uncertainty," he added.

United Airlines

United Airlines reported fuel expenses were up by $340 million, a 12.6% increase from the same period last year.

In its earnings report, the airline said it is already reducing its capacity due to higher fuel prices.

CEO Scott Kirby said the airline plans to "recover 100% of fuel costs," but they would need to earn an extra 15%-20% per passenger.

"Realistically, there probably isn't enough time to make up 100% of the fuel price increase this year, but I feel very good about 100% recovery and getting to double-digit margins in 2027," he added.

Chief Financial Officer Mike Leskinen also said: "We believe we have the ability to pass on the increase in fuel due in large part to our brand loyal customers, continued demand strength, and preference to fly United, even at higher fares."

American Airlines

American Airlines reported that aircraft fuel and related taxes were up 13.2% or $341 million, compared to the first quarter of 2025.

Plus, CEO Robert Isom told investors that it had spent an extra $400 million on fuel since January.

The airline also expects to spend an additional $4 billion on fuel throughout the year, Chief Commercial Officer Nat Pieper said.

"Obviously, if fuel continues through the third quarter into the fourth quarter, we are going to see some more broad industry capacity reductions," he added.

Southwest Airlines

Southwest Airlines said its fuel costs were up by $164 million in the first quarter.

While it previously issued guidance for costs of $2.40 a gallon, it ended up being $2.73.

However, it expects a significant jump ahead, assuming second-quarter fuel costs of $4.10 to $4.15 per gallon.

"Fuel prices are much higher, and if that is sustained, it will require higher ticket prices to offset that increase in fuel," CEO Bob Jordan said in the earnings call.

He also pushed back against airlines estimating how much of the fuel increase they could recover. "It's going to be dictated by market conditions, not by some academic formula," Jordan said.

The Southwest CEO added that you can't predict at what point ticket pricing will lead to "demand destruction."

"We're taking actions against the things that we can control," Jordan said, such as increasing checked bag fees by $10.

American, Delta, and United also increased their bag fees by $10 in April.