Perhaps the most important non-GAAP earnings disclosure from airlines is total revenue per available seat mile, known as TRASM — but we’ve written about TRASM plenty of times before, so today we’re looking at another metric: average fuel cost per gallon.

This is a non-GAAP disclosure that all major airlines report. We like it because fuel is one of the single largest expenses an airline has, and average cost per gallon gives you a normalized sense of that cost pressure over time. You can find it via the Disclosures & Footnotes page; just pull up the airline’s earnings release and search for “fuel” or “gallon” and you’ll find it momentarily.

Figure 1, below, charts average fuel costs per gallon for six major U.S. airlines from 2021 through 2024 (although please note that Southwest ($LUV) and JetBlue ($JBLU) haven’t yet filed their Q4 numbers). 

As you can see, all the airlines endured painful price hikes in 2022. Presumably that was driven by Russia’s invasion of Ukraine and overall inflation, both of which sent oil prices soaring that year. 

Average prices have since taken a bumpy downward path since then, but individual airlines often had average costs that vary considerably. For example, Alaska Air ($ALK) paid considerably more for fuel at the end of 2023, while Delta Air Lines ($DAL) has managed to keep its average fuel costs lower than all its rivals for pretty much all of the last three years. 

Airlines make other fuel-related disclosures, too. For example, they typically offer forward-looking guidance on estimated fuel costs, which you could then cross-check a few quarters later to see how well an airline you follow did or didn’t meet its expectations. They also report total fuel consumed and total money spent on fuel.

That said, remember that fuel consumed and total fuel cost can’t really give you an apples-to-apples comparison among airlines, since those numbers will vary wildly depending on an airline’s size, type of aircraft used, and routes flown. (Hence we like average fuel cost per gallon, which is more about an airline’s ability to plan for and hedge future costs.)

And of course, operating metrics about fuel look at an airline’s costs. Calcbench also tracks several metrics more related to an airline’s revenue, such as— 

• TRASM, or total revenue per available seat mile

• CASM, costs per available seat mile

• Load factor, which is the percentage of seating capacity filled by customers

• Percentage of revenue coming from passengers

Want to conduct your own easy analytical adventure in the airline industry? If you are a Professional-level Calcbench subscriber and have installed the Calcbench Excel Add-In, all you need to do is download our template from DropBox. The template will then automatically pull the latest quarterly data as the airlines file earnings reports. 

After that, the sky’s the limit!