Southwest Personal Item Size 2026: What Fits Under the Seat

Southwest doesn’t publish a size limit for personal items. Its official rule is that every passenger can bring one personal item that fits under the seat in front of you, plus one carry-on bag up to 24 × 16 × 10 inches including wheels and handles, and both are free on every fare. A figure of 16.25 × 13.5 × 8 inches is often quoted for the space under a Southwest seat; it isn’t on Southwest’s page, but it is a sensible target. Our top pick is the Sherpani Soleil AT (15 × 11 × 5.5 inches). For the most space, choose the Aerolite 16.25 × 13.5 × 8 inch backpack, and for a bag you can roll, the American Tourister Take2Cabin.

Rules below were checked against Southwest’s official carryon and personal item policy and travel fees pages on 11 November 2026. Southwest changed its bag policy recently, so recheck those pages before you fly.

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Our Top Southwest Personal Item Picks

Sizes are published outside dimensions (height × width × depth). Metric bags are converted from 40 × 30 × 20 cm.

How We Selected the Best Personal Item Bags for Southwest

Because Southwest doesn’t publish a personal-item size, we treated the commonly quoted 16.25 × 13.5 × 8-inch figure as a conservative ceiling and compared each bag’s published dimensions against it:

• Published outside dimensions at or under 16.25 × 13.5 × 8 inches on every side
• How much margin each bag leaves once packed, since soft bags bulge
• Empty weight, because your personal item often carries your heaviest essentials
• Laptop, tablet and quick-access storage for the things you want at your seat
• A luggage sleeve or wheels so it pairs easily with a Southwest carry-on
• A mix of styles (anti-theft convertible, max-size backpack, wheeled bag and light daypacks)

These are editorial picks based on manufacturer and retailer specifications and our related LuggageRate guides. We haven’t checked these bags under a Southwest seat, so measure your own bag after packing. Labels such as “Southwest approved” are a seller’s claim, not Southwest’s.

What Is the Southwest Personal Item Size?

Southwest’s official carryon and personal item policy gives no dimensions for a personal item. It says only that the personal item goes under the seat in front of you, and its travel-fees page describes it as a smaller, personal type item that can be stowed under a seat or in an overhead compartment.

You will often see 16.25 × 13.5 × 8 inches quoted as Southwest’s under-seat maximum, and some bag makers, including Aerolite, build bags to it. Southwest’s current page doesn’t include that figure, so treat it as a practical target: a bag at or under 16.25 × 13.5 × 8 inches should fit under a standard seat, and anything smaller gives you more legroom. Under-seat space also varies a little by seat, so a slim, soft bag is the safest choice.

For comparison, American Airlines publishes an 18 × 14 × 8-inch personal-item limit; see our American Airlines personal item size guide. A bag that fits 16.25 × 13.5 × 8 inches also fits American’s limit.

Southwest Personal Item vs Carry-On Rules

Southwest lets every ticketed passenger bring one carry-on bag and one personal item on board for free, on every fare.

• Carry-on bag: up to 24 × 16 × 10 inches (length × width × height). Wheels, handles and any attachments count toward those dimensions, and the bag goes in the overhead bin. Southwest’s examples are a roller bag or small suitcase.
• Personal item: no published dimensions. It goes under the seat in front of you.
• Weight: Southwest doesn’t publish a weight limit for either bag, so the practical check is whether you can lift your carry-on into the bin yourself.
• Extra or oversized bags: if a bag is too large to carry on, or you have more than one carry-on or personal item, Southwest asks you to check it at the ticket counter before you go to the gate.
• Partner flights: if your itinerary includes a partner airline, its carry-on and personal-item rules may differ.

Southwest’s 24 × 16 × 10-inch carry-on allowance is larger than the 22 × 14 × 9 inches most U.S. airlines use. To pick a suitcase that makes the most of it, see our best carry-on luggage for Southwest Airlines guide.

What Counts as a Personal Item on Southwest?

Southwest’s own examples of a personal item are:

• A purse, including crossbody bags
• A briefcase or laptop case
• A backpack
• A pillow or blanket
• A small camera

Neck pillows don’t count toward your carry-on limit. A pet carrier counts as either your carry-on or your personal item, so if you fly with a pet in the cabin you give up one of the two. Because Southwest lists a backpack as a personal item, a travel backpack, tote or small duffel is fine as long as it fits under the seat in front of you. Bring a second bag of that size and it becomes your carry-on.

Do Wheels and Handles Count for a Southwest Personal Item?

For the carry-on, yes: Southwest says wheels, handles and any attachments count toward the 24 × 16 × 10-inch limit. The personal-item rule doesn’t mention wheels because it has no dimensions at all. If you use a wheeled underseat bag such as the Take2Cabin, measure it with the wheels and handle and check it against 16.25 × 13.5 × 8 inches to be safe.

For soft bags, measure after you pack: stand the bag upright, measure from the floor to the top, and measure depth at the deepest pocket. Depth is usually the dimension that stops a bag sliding under a seat.

Southwest Checked Bags Are No Longer Free for Most Fares

Southwest ended free checked bags for most fares. According to its travel fees page, checked-bag fees now apply to Basic, Choice and Choice Preferred fares. Choice Extra fares and Rapid Rewards A-List Preferred members get two free checked bags, while A-List members and Rapid Rewards credit cardmembers get their first checked bag free. Your carry-on and personal item stay free on every fare.

That makes a well-packed personal item more valuable. Pair a roomy carry-on with a personal item that uses the space under the seat and many travelers can skip checking a bag. If you do check one, Southwest’s checked baggage policy allows up to 62 inches (length + width + height) and 50 lb before oversize or overweight fees; our best 62-inch luggage guide covers suitcases built to that size.

1. Sherpani Soleil AT Anti-Theft Travel Backpack

Best Overall Southwest Personal Item

The Sherpani Soleil AT is our top personal item for Southwest because it leaves plenty of room under the seat and still carries a full-size laptop. Sherpani lists it at 15 × 11 × 5.5 inches and 18 liters, more than an inch shorter, two and a half inches narrower and two and a half inches shallower than the 16.25 × 13.5 × 8-inch figure often quoted for Southwest. That margin matters because Southwest’s only real requirement is whether the bag slides under the seat in front of you, and a slim bag does that even when it is full.

It is a 3-in-1 bag: wear it as a backpack, carry it by the tote handles, or use the 55.5-inch removable strap as a crossbody. Inside is a padded sleeve for laptops up to 15.6 inches, phone and pen pockets, a key leash and a bottle pocket, and outside there are two zip pockets, two bottle pockets and a back sleeve that slides over a suitcase handle. The anti-theft details are what set it apart: RFID protection, zipper lock tunnels, a clip lock on the main compartment, a chair-lock cable, an anti-slash bottom and a slash-proof crossbody strap. The listing quotes 2 lb 2 oz (the Amazon spec table says 9.6 oz, which looks wrong), and Sherpani backs it with its Fearless Lifetime Warranty. It is also our anti-theft pick in the best travel totes with a zipper guide.

Best for: Travelers who want a secure, slim bag for a laptop and essentials that tucks under the seat with room to spare.

Pros

• 15 × 11 × 5.5 inches leaves margin on every side of 16.25 × 13.5 × 8
• Backpack, tote or crossbody carry
• Padded 15.6-inch laptop sleeve and a luggage sleeve
• RFID pocket, lockable zippers and slash-resistant panels
• Fearless Lifetime Warranty

Cons

• 18 liters holds essentials and a change of clothes, not a weekend wardrobe
• Heavier than a plain nylon tote
• Amazon’s listed weight conflicts with the bullet points

2. Aerolite 16.25 x 13.5 x 8 Inch Max Carry-On Backpack

Best Max-Size Underseat Backpack

If you want the biggest bag you can reasonably slide under a Southwest seat, the Aerolite Max Carry-On Backpack is built to 16.25 × 13.5 × 8 inches, the size Aerolite markets as the Southwest maximum. Southwest itself doesn’t publish that number, so treat it as a target rather than a guarantee, but it is the most capacity in this guide: a listed 29 liters at 1.12 kg (about 2.5 lb).

It is a 3-in-1 bag: wear it as a backpack (the padded straps stow in a zip pocket), sling it over your shoulder with the air-cushioned strap, or carry it like a holdall by the top and side handles. Inside are three zipped compartments, including a main section with packing straps, a tech pocket with a tablet pouch for screens up to 10.1 inches, and a waterproof toiletry pocket. There is also a side bottle holder and an external USB port that you wire to your own power bank (not included). The outer fabric is made from recycled plastic bottles.

Make sure you choose the 16.25 × 13.5 × 8-inch model, not Aerolite’s larger 18 × 14 × 9-inch backpack. Aerolite sells it through its UK store, so check delivery and returns before you order. The same bag is the personal-item pick in our American Airlines personal item size guide.

Best for: Travelers who want to pack as much as possible into a personal item and pair it with a Southwest carry-on.

Pros

• Built to 16.25 × 13.5 × 8 inches, the most space in this guide
• 29 liters at a listed 1.12 kg (about 2.5 lb)
• Backpack, shoulder-bag or holdall carry
• Tablet pouch, toiletry pocket, bottle holder and USB port

Cons

• No margin on any side, so don’t overstuff the pockets
• No dedicated laptop sleeve listed (tablet pouch only)
• Sold through Aerolite’s UK store

3. American Tourister Take2Cabin Wheeled Backpack

Best Wheeled Underseat Bag

Want to roll your personal item rather than carry it? The American Tourister Take2Cabin is a wheeled backpack built to 40 × 30 × 20 cm (about 15.75 × 11.8 × 7.9 inches), so it stays inside the 16.25 × 13.5 × 8-inch figure with half an inch to spare on height, almost two inches on width and a sliver on depth. American Tourister lists 24.5 liters and 1.5 kg (about 3.3 lb).

When you don’t want to roll it, the shoulder straps come out of a zippered back pocket whose lid also covers the wheels, so they don’t dirty your clothes. There is an easy-access front pocket, an elastic mesh side pocket for a bottle, elastic cross straps to hold clothes in the main compartment, and a sleeve for stacking it on a larger suitcase. The outer fabric is 100% recycled PET polyester. Wheels and a handle add weight and take a little room from the inside, so it is heavier than the backpacks above. It is also a pick in our best 40x30x20 underseat bags guide.

Best for: Travelers with long walks through the airport who want to roll their personal item and keep their back free.

Pros

• About 15.75 × 11.8 × 7.9 inches fits inside 16.25 × 13.5 × 8
• Wheels and a telescopic handle, plus stowable backpack straps
• 24.5 liters with a front pocket and cross straps
• Recycled PET polyester outer

Cons

• Heaviest pick at a listed 1.5 kg
• Wheels and handle use some interior space
• Depth is within a tenth of an inch of 8 inches, so keep the front pocket flat

4. CabinFly Pacemaker 40x30x20 Backpack

Best Two-Compartment Backpack

The CabinFly Pacemaker is a simple, light underseat backpack at 40 × 30 × 20 cm (about 15.75 × 11.8 × 7.9 inches), the same footprint as the Take2Cabin without the wheels. CabinFly lists 24 liters and 685 g (about 1.5 lb), so it holds about the same as the wheeled bag at less than half the weight.

It has two compartments of different sizes, which makes it easy to keep a laptop and documents apart from clothes, and the listing adds a laptop compartment for devices up to 15.6 inches, a bottle holder, a carry handle and water-resistant 600D polyester. It was designed for strict European budget airlines, so it is a good choice if you also fly Ryanair or Wizz Air. Amazon wouldn’t confirm U.S. delivery when we checked, so look at the delivery estimate before you order. See it in our best 40x30x20 underseat bags guide.

Best for: Travelers who want a light, no-fuss backpack with room for a laptop and a change of clothes.

Pros

• About 15.75 × 11.8 × 7.9 inches fits inside 16.25 × 13.5 × 8
• 24 liters at about 685 g
• Two compartments and a 15.6-inch laptop space
• Also fits strict 40 × 30 × 20 cm budget-airline limits

Cons

• Fewer pockets and features than the Sherpani or Aerolite
• Depth is within a tenth of an inch of 8 inches
• U.S. delivery not confirmed when we checked

5. Cabin Max Metz Stowaway 20L

Lightest Underseat Bag

The Cabin Max Metz Stowaway is the lightest bag here at a listed 500 g (about 1.1 lb). It measures 16 × 10 × 8 inches (40 × 25 × 20 cm), a quarter-inch under the 16.25 × 13.5 × 8-inch figure on height and three and a half inches narrower, with an exact 8-inch depth.

It opens like a suitcase, and side compression straps pull a full 20-liter load tight. The front pocket has slots for a tablet, travel documents, pens and tickets, and the backpack straps, top handle and back panel are padded. Cabin Max quotes a three-year warranty. Amazon showed only one left in this Paradise colour when we checked, so it may sell out. It also appears in our best 40x30x20 underseat bags guide.

Best for: Light packers who want the smallest, lightest bag for essentials under the seat.

Pros

• Lightest pick at about 1.1 lb
• 16 × 10 × 8 inches with room to spare on width
• Suitcase-style opening and compression straps
• Three-year Cabin Max warranty

Cons

• 20 liters is the smallest capacity here
• No padded laptop sleeve listed
• Low stock in this colour when we checked

Buying Considerations for a Southwest Personal Item

Start with the published outside dimensions, not a bag’s liter capacity, and compare them with 16.25 × 13.5 × 8 inches. Exact-fit bags such as the Aerolite give you the most space but no margin, while slimmer bags like the Sherpani slide under the seat more easily when full. Think about how you carry it, too: a wheeled bag saves your back on long walks but weighs more, and a convertible bag doubles as a day bag at your destination. If you carry a laptop, check the sleeve size: the Sherpani and Pacemaker take up to 15.6 inches, while the Aerolite and Metz list only a tablet pocket.

Flying other airlines on the same trip? Personal-item rules vary, so check before you buy one bag for everything. Our Frontier and Allegiant guides cover budget carriers where the personal item is the only free bag, our Delta and United Airlines guides explain their under-seat rules, and our luggage size guide helps you match a bag to your trip length.

Final Verdict

For Southwest flights in 2026, remember that the airline doesn’t publish a personal-item size: your bag just has to fit under the seat in front of you, and 16.25 × 13.5 × 8 inches is a sensible ceiling. The Sherpani Soleil AT is our best all-round personal item, with room to spare and a padded laptop sleeve. Choose the Aerolite 16.25 × 13.5 × 8 inch backpack for the most space, the American Tourister Take2Cabin if you want wheels, the CabinFly Pacemaker for a light two-compartment backpack, and the Cabin Max Metz Stowaway if you pack light. Whatever you pick, measure it packed and recheck Southwest’s official baggage pages before you fly.