Key Takeaways: You can book premium economy seats at coach prices on selected wide-body domestic routes.

While the major U.S. airlines operate single-aisle aircraft like the Airbus A320 and Boeing 737 for many domestic routes, United Airlines, American Airlines, and Delta Air Lines also utilize twin-aisle jets.

Typically, airlines deploy wide-body jets for longer flights, offering an enhanced inflight experience with amenities such as seatback screens, power outlets, and larger overhead compartments. The standout feature is the chance to secure premium economy seating for the cost of an extra legroom seat.

Here’s what you should know about snagging a 'free' upgrade to a premium economy seat on your upcoming flight.

Tips for discovering 'free' premium economy seating options.

With a few exceptions where airlines designate premium economy as a separate cabin (mainly on long-haul flights to Hawaii and select transcontinental routes by Delta), you can book premium economy seats on various domestic flights using wide-body aircraft under names like United Economy Plus, American Premium Economy, or Delta Comfort+.

This means that you can use your complimentary extra legroom seating—an elite status perk—to book premium economy seats. If you lack elite status, you can still pay to select these seats. While you can expect similar benefits and service as in an extra legroom seat, premium economy offers an enhanced experience.

When reserving a flight, make sure to verify the type of aircraft. Check the seat map if you notice wide-body jets such as the Airbus A330 or A350, or Boeing 767, 777, or 787 being used.

If you know what to observe, you can identify premium economy seats.

For instance, the seat arrangement in premium economy will differ from that of the standard economy section. On Boeing 777s, the typical premium economy setup features a 2-4-2 configuration, in contrast to the regular economy's 3-4-3. This is because premium economy seats are designed to be wider.

In United's Premium Plus cabin, the row numbers for premium economy (rows 20, 21, and 22) stand out significantly from the Economy Plus cabin (rows 30 to 34, 40, and 41). All blue seats, including those in premium economy, are available for reservation as Economy Plus on this aircraft. This means that Premier Silver members can secure them for free during check-in, while Premier Gold, Premier Platinum, Premier 1K, and United Global Services members can select these seats at no cost during booking. United's generous Economy Plus companion rules continue to apply.

American Airlines makes it a bit more complex. You can't easily identify premium economy just by the row number, so be vigilant when reviewing the seating chart. Premium economy features a 2-3-2 configuration on this aircraft, unlike the standard 3-3-3 layout found in other sections of the plane.

All orange seats, including those in premium economy, can be booked as Main Cabin Extra (American's extra legroom option) on this flight.

Delta Air Lines often features larger premium economy cabins compared to United and American, labeling some domestic premium economy seats as Comfort+. If your Medallion status grants you access to complimentary Comfort+, you can secure one of these seats at no cost.

If you're dissatisfied with the available premium economy seats when booking or if they’re fully booked, set a seat alert with ExpertFlyer. (ExpertFlyer is owned by TPG's parent company, Red Ventures.) You'll receive an email notification if a seat opens up. ExpertFlyer has helped me avoid undesirable center premium economy seats on several occasions.

Comparing premium economy seats with domestic first-class seats

Now for the exciting part.

Premium economy seats offer a notable upgrade over standard extra legroom options. In fact, they are comparable to what you'd expect from a domestic first-class seat on a single-aisle aircraft.

Let’s look at seat dimensions using United's fleet. These measurements are sourced from United's website.

While the width may not be as spacious as first class on a Boeing 737, the pitch and recline in premium economy surpass what you'd find in narrow-body first class.

Now, let’s revisit this example.

For $397, Premier Gold members and above can book a premium economy seat—comparable to a first-class seat priced over $3,000. Naturally, the first-class option includes a full meal, extra checked luggage, Premier Access, and enhanced service. However, if you focus solely on the seating, the two options are fairly similar.

United may alter its aircraft, which could result in being assigned a standard Economy Plus seat, but in my experience, that rarely occurs.

Domestic routes featuring wide-body aircraft

Here are some domestic flights where United, American, and Delta typically utilize wide-body services (as of now). Our tests indicate that you can book premium economy seats as extra legroom options on these routes, which are primarily on busy paths to, from, or between major hubs. Please note that these routes may change.

United

• San Francisco International Airport (SFO) to Washington, D.C.'s Dulles International Airport (IAD), Houston's George Bush Intercontinental Airport (IAH), Chicago's O'Hare International Airport (ORD), Honolulu's Daniel K. Inouye International Airport (HNL), and Kahului Airport (OGG) on Maui.
• Los Angeles International Airport (LAX) to IAD, ORD, HNL, and IAH.
• Denver International Airport (DEN) to ORD and IAD.
• Newark Liberty International Airport (EWR) to IAH.

Keep in mind that United also offers multiple daily premium economy flights from SFO and LAX to EWR, which are sold as a distinct cabin.

American

• Miami International Airport (MIA) to Dallas Fort Worth International Airport (DFW), Phoenix Sky Harbor International Airport (PHX), Charlotte Douglas International Airport (CLT), Tampa International Airport (TPA), LAX, and ORD.
• DFW to Orlando International Airport (MCO), Cancun International Airport (CUN) in Mexico, ORD, and LAX.
• Philadelphia International Airport (PHL) to CUN and PHX.

Delta

• Hartsfield-Jackson Atlanta International Airport (ATL) to Boston Logan International Airport (BOS), Minneapolis-St. Paul International Airport (MSP), Seattle-Tacoma International Airport (SEA), Detroit Metropolitan Wayne County Airport (DTW), New York City's John F. Kennedy International Airport (JFK), and LAX.
• LAX to DTW.

Conclusion

Alongside a dedicated cabin located near the front of the aircraft, premium economy seats typically provide an inflight entertainment system with a remote control, enhanced seat recline, a small footrest, and (my personal favorite) a tray table built into the armrest that’s spacious enough to prevent elbow conflicts with your neighbor.

Although airlines can modify their aircraft types at any time, booking premium economy for the cost of an extra legroom seat remains one of the best-kept secrets for domestic flights. The next time you notice a wide-body jet on a flight you’re thinking about, keep in mind that some extra legroom seats might offer significantly better comfort than others.