I was fortunate enough to snag extra legroom seats on both of my flights last week; exit row on a legacy 737-700 which had not been modified and an aisle seat in the second row of a -800 series plane that had been modified. The flights were both long (to and from the west coast), so I was happy to have the extra space. But it got me thinking….
Now that Southwest is selling extra legroom seats for travel starting January 27th of next year, how do they compare to the legacy “big 3” of American, United, and Delta when it comes to charging for these seats? Overall, the answer surprised me!
Methodology
This one was tough to get to a clean, apples to apples comparison. Different routes are different lengths (and thus different cost for those seats). Southwest allows buying these seats from their Basic fares where the others do not. This impacts the results on the extra legroom seat upgrade cost vs the base fare cost and essentially penalizes Southwest in the calculation. On the other hand, the others tend to include things like alcoholic beverages in these fares where Southwest does not. General fare prices were different as well which impacts the ratio of the seat cost.
To optimize the comparison, I looked at 7 different routes on different days for early 2026. In each case I wanted to make sure that 1) these were nonstop routes and 2) routes served by Southwest and at least one other carrier for the same markets. I tracked the fare range for the nonstop flights offered that day as well as the range of cost to upgrade to the extra legroom seats. For example, all but Delta had different costs for different specific seats, i.e. an extra legroom middle seat was typically cheaper than an aisle or window seat.
The routes and dates I selected were:
- STL to MIA on Feb 21st
- STL to DEN on Mar 11th
- STL to MSP on Mar 25th
- LAX to Dallas (DFW/DAL) on Mar 14th
- LAX to Houston (HOU/IAH) on Feb 28th
- Chicago (MDW/ORD) to MCO Jan 31st
- SEA to DEN on Apr 1st
Results
Overall, and to my surprise, Delta was actually “best” both in terms of average cost of the extra legroom seat and the ratio of that cost vs the ticket cost. Delta was also the only carrier that charged a flat rate for any of their extra legroom seats, at least on the routes I looked at. United was consistently the worst on head-to-head routes. Southwest and American tended to be quite close to each other in terms of the seat cost. Here is a summary:
If you are interested to see the raw data by route, here you go:
Conclusion
If extra legroom seating is important to you, I would stay away from United unless the standard economy fare is really cheap. If more than one carrier flies your route nonstop, it is definitely worth comparing the full price vs just the seat upgrade price because there is a lot of variation.
Fare bundles make this even more opaque because things like ability to cancel, checked bags, and the value of mileage earning become important to making the decision. Overall, decide which features are most important to you and make sure you are getting the best value with those features included.
TL;DR: With Southwest rolling out extra legroom seats for flights in 2026, it was interesting to see how their pricing compared to the legacy carriers. While not as cheap as Delta, Southwest was unique in allowing Basic economy fares to still pay for extra legroom seats – effectively lowering the total cost.
