Charts show how the Iran war has pushed ticket prices sharply higher on 3 major US airline routes

• War in the Middle East has pushed fuel costs, and therefore airfares, sharply higher.
• Business Insider charted the increase in ticket prices for three major flight paths in recent weeks.
• Fares from New York to LA, New York to London, and from the US mainland to the Caribbean have jumped.

Your next flight could be twice as expensive because the Iran war is causing volatility in oil prices.

Brent crude is up more than 50% over the past month, to around $101 a barrel. Jet fuel costs are rising faster. The Argus US Jet Fuel Index is up 72% over the same period.

That spells difficulty for airlines because jet fuel is typically their biggest expense after labor. While many airlines around the world hedge against fuel costs, most American ones do not.

Using data from Deutsche Bank, Business Insider charted rising airfares in three major markets.

The data looks at the lowest available published fares 21 days in advance of the flights. The published fare doesn't necessarily mean a ticket has been purchased for that amount, the Deutsche Bank research analysts said.

Cross-country flights, often known in the industry as transcontinental flights, have seen the biggest week-over-week spike — more than double, on average.

New York to Los Angeles is the country's busiest domestic route, with a capacity of 3.4 million seats out of JFK Airport last year, according to OAG data.

The average price of a transcontinental flight has risen from $167 to $414, Deutsche Bank's analysis showed. In the past week, the average has spiked 107%.

United Airlines is offering flights from Washington Dulles Airport to San Francisco for $502, up from $149 a month ago.

International business travellers are also seeing flight prices rise.

New York to London is the country's most popular international route, and the 10th-busiest in the world. Nearly 4 million seats were scheduled on flights between JFK and Heathrow last year, per OAG.

While the average Transatlantic flight is some 40% more expensive than a month ago, there are bigger rises for the New York-London route. However, it also appears more volatile here with a big dip last week.

Delta Air Lines' service is up from $285 to $553 over the past month, while United's is up to $846. That's a 177% rise compared to a week earlier, according to Deutsche Bank's analysis.

There's bad news for vacationers, too.

Flights to the Caribbean on March 27 are up 58% on average compared to a week before.

JetBlue's flight from New York to Santo Domingo, Dominican Republic, has risen from $165 to $566 on March 27.

Compared to a year earlier, that's a more than fourfold rise, Deutsche Bank found.

Southwest Airlines' flight from Baltimore to Montego Bay, Jamaica, has more than doubled over the past week. And Alaska Airlines' service from Los Angeles to San Jose, Costa Rica, is up 40% compared to a week earlier or 120% versus a year ago.