Accompanying this analysis is a dashboard of oil and jet fuel flows across reporting countries. You can access the dashboard here.

As of April 23, 2026, the Strait of Hormuz is closed. Kind of.

Best we can tell, the Strait was open, inasmuch as ships that paid the Iranian toll were allowed to pass, then closed as the U.S. set up a blockade south of the Strait in an attempt to build leverage for negotiations that did not happen. Iran has since attacked and boarded several ships, effectively driving insurance rates to a point where ships can no longer pass through the strait, toll or no toll.

Even though the financial windfall for Iran would have been stunning, countries facing shortages of fuel were happy to pay — at least less unhappy than the alternative. And it is that alternative we look at from the aviation perspective today. What’s missing from the global jet fuel market, and why does it seem like jet fuel is impacted more heavily than others?

Short answer: because it is.

Oil goes into a refinery, and jet fuel comes out the other side along with other stuff.

From a perspective of refining oil, there is no need for us to dive into the complex refining process itself. Petrochemical engineers receive Master’s and Doctorate degrees to understand the magic of the proverbial black box between crude oil and jet fuel. But for our purposes of understanding jet fuel supply and the challenges commercial aviation faces, it’s a useful abstraction: oil goes in, jet fuel comes out.

How much? About 10% of a barrel of oil can be turned into kerosene-type jet fuel. That’s typically about 4 gallons of jet fuel for every barrel of oil (42 gallons of oil).

But not all crude oils produce jet fuel equally. You’ve likely heard of terms like light sweet and heavy sour crude. Those terms relate to the oil's viscosity and sulfur content. Light sweet is better used to refine gasoline, while heavy sour is geared more for diesel and fuel oils. Jet fuel sits in a narrow band in between gasoline and diesel, competing heavily with diesel for output.

And this competition can be problematic for jet fuel, where diesel priority can replace much of the kerosene-type jet fuel if needed. To some extent, it becomes a matter of priority.

Much of North America and Australia’s oil is of the light sweet variety. The Middle East has a more traditional blend that is closer to heavy sour (though none is as heavy or sour as the crude under Venezuela - hard to get to and closer to tar than what we may think of as oil).

Point being, jet fuel still requires some sour oil, the majority of which comes from the Middle East or Russia. It’s for this reason that the United States, the largest producer of oil in the world, still imports oil. It doesn’t produce the type that can make everything. It’s also why jet fuel and diesel prices in the U.S. have risen significantly higher than gasoline prices. It still needs some of the heavy sour.

Since jet fuel rests between gasoline and diesel in the refinery process, it’s also sandwiched. The band for refining jet fuel is relatively narrow, and with gasoline and diesel availability much more of a concern for governments and their potentially dangerous public, jet fuel gets squeezed.

Refineries can stretch (to a point) how much of each type of fuel gets refined from a barrel of oil, but that’s of little use to jet fuel right now. Political impacts from fuel prices are much stronger for gasoline and diesel - literally fueling economies - and so the two products are prioritized. What’s one way to keep gasoline and diesel prices in check? Prioritize refining away from the middle ground where jet fuel sits. That’s not to mean jet fuel is not being refined, just that given the possibility of seeing gasoline or diesel prices go parabolic, countries are not likely to provide the same level of protection for jet fuel.

In short, from a governmental perspective, gasoline and diesel prices are more dangerous than jet fuel prices.

The further challenge is that oil is not necessarily refined where it is found. Take Australia, as a fascinating example. Australia produces a significant amount of oil in its western states, but refines and consumes most petroleum products in its eastern states. As a result, Australia exports almost all of its oil and imports roughly the same amount. It’s closer and easier to export the light sweet crude to other countries in Southeast Asia and then import the heavier sour mixes from elsewhere.

And yet, Australia still directly imports much of its refined jet fuel, much of it from Korea.

South Korea’s refining setup is another unique situation. It is a country that produces no crude oil, but is the top exporter of jet fuel in the world outside of the Middle East. South Korea specializes in refining, importing crude oil, and exporting large quantities of refined products, including jet fuel. Much of the crude inbound to South Korea arrives from the Middle East - about 70%.

Speaking of the Middle East, aside from the crude oil exports from the region, refined products like jet fuel are were also exported through the Strait of Hormuz. Even though jet fuel production and demand aren’t reported to the Joint Organizations Data Initiative (JODI) database on which we are relying for this analysis, estimates are that approximately 10% of global jet fuel exports are traditionally handled through the region. Virtually none of it is bypassed through pipelines, leaving the vast majority of jet fuel exports with the requirement to transit the strait that isn’t exactly transitable at the moment.

There is no one database to show how much jet fuel a country has, where it gets its jet fuel, and how much of it is imported through the Strait. However, we have combined data from multiple databases from the EIA, IEA, JODI, and UN Comtrade to create a picture of likely shortages.

And yet, this picture leaves a key factor unknown that will greatly impact which countries run short, and which have enough jet fuel to last. Despite where refining countries sourced crude in the past, that is now up in the air. New agreements are being made on the fly, particularly in East and Southeast Asia where reliance on the Middle East has been high.

For those countries without sufficient crude production of their own, the race to source crude oil is on. The problem is, there’s not enough to go around. Even if South Korea typically provides its large refining base with crude from the Middle East, the country will be looking for alternatives - and competing with those countries looking to do the same.

But there is only so much to go around. For every barrel South Korea finds and an alternative location from which to source, a barrel is not available for the country that used to receive it.

However, jet fuel imports are easier to track. If jet fuel is imported, it’s needed. The United Kingdom typically imports the most jet fuel, despite having sufficient crude oil production. The bottleneck is refining capacity.

Similarly, Mexico and Canada are net importers of jet fuel for different reasons. It’s much easier to pipe in jet fuel from across the border than from the various parts of the country where oil is produced or refined. Mexico, for instance, benefits from the proximity to the large refineries in South Texas, while Eastern Canada is separated from its oil source and has easy access to the U.S. pipeline system much closer.

Yet, some countries rely almost entirely on refined imports. Iceland, for instance, retains no refining capacity. But it is not the small countries in the North Atlantic that raise concern, but rather those in the South Pacific and the Indian Ocean.

Already, reports of shortages are arriving from Vietnam, Cambodia, India, Sri Lanka, and the Philippines. Those are likely to spread in the region as stocks run low.

And so our estimates are based on a specific methodology. We assume countries that export oil or jet fuel will prioritize their own demand first. We also assume that jet fuel stocks reported at the end of 2025 have not materially changed by the start of the conflict.

Finally, we divide the net demand per month by the total storage available and running refinery potential to feed the country’s own domestic jet fuel needs. The result is the months of stores remaining.

It’s an estimate, and probably better defined by what we don’t know rather than what we do. Here’s what we don’t know:

What happens when jet fuel stores start to run dry?

We actually have a good example of how jet fuel shortages may play out - Cuba.

Cuba just went through a critical energy crisis after the blockade set up by the United States. Even though the island country refines much of its own fuel needs, no crude oil was allowed in. The lights went out, and flights stopped operating.

But the impact to aviation was much more affected by the lights going out than the lack of fuel. Some flights continued to operate, predominantly from Florida, where aircraft could be loaded with enough fuel to make the round trip. Canadian airlines were not as lucky and were forced to slash flights.

But, even with the ability to get an airplane there and back, nobody wanted to go. This is where the impact of the jet fuel shortage may result in a much deeper downturn for aviation. As Cuba has shown, energy’s impact on the overall economy was much more impactful to aviation than the ability to fuel aircraft. In a jet fuel shortage, airplanes stop flying. In an overall energy shortage, people want airplanes to stop flying. The difference is both slight and everything.

This highlights what we believe to be the greatest risk to aviation of the jet fuel shortage - flight shaming, or a version of it. Once relegated to climate concerns in Europe, aviation could be faced with negative publicity amid public panic over energy. Consider waiting hours in line to fill your vehicle, only to watch a 777 pass overhead at takeoff power. The optics are terrible.

Already, we are hearing of explicit calls to limit air travel amid high gasoline and diesel prices. Aside from the obvious economic impacts to aviation that fuel shortages bring, air travel is uniquely susceptible and visible to an angry public. In this way, it’s not the availability and price of jet fuel that poses the threat to aviation, but rather the availability and price of gas and diesel that do.

Which brings us back to the geographical share of the shortages. How will countries react to a dislocated crude oil supply chain? Will they hoard the stores they have? Europe may not receive as high a percentage of oil from the Middle East as Asia, but they’re now competing for the alternative sources with those now looking to replace.

The immediate concern is for the peak summer 2026 season, which may not occur. But the lingering effects of fuel shortages could extend for many months beyond the resumption of normal operations in the Strait of Hormuz - whenever that may be.

And we haven’t even started discussing airline profitability, yet.

If you’d like to recreate the flow of fuel charts, we’ve created a dashboard. We have accepted the numbers as reported, so they may not add up in various countries. It showcases the challenges when trying to estimate what comes next.

Author’s note: I am not an expert in oil refining, nor did I stay at a Holiday Inn Express last night. Point being, there are likely nuances to this market I have missed. It happens, but the research into a new topic was meant to limit how those missed nuances may impact aviation. If you have any context to add, please let us know.

Notably absent from the stock charts this week is Spirit Airlines, up over 150% after the U.S. government signaled a bailout for the airline.

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