The Southwest carry on size limit is 24 × 16 × 10 inches, and that includes wheels, handles, and anything else that sticks out. You also get one personal item that fits under the seat in front of you, and both fly free. The limit itself hasn't changed in 2026, but enforcement has, so this guide covers the exact rules, how strict the gate sizers actually are, what a too-big bag costs you now, and which carry-ons fit with room to spare.
Southwest carry-on rules at a glance
| Rule | Southwest policy (as of July 2026) |
|---|---|
| Carry-on size limit | 24 × 16 × 10 inches (61 × 41 × 25 cm), wheels and handles included |
| Carry-on allowance | 1 bag, stored in the overhead bin |
| Personal item | 1 item that fits under the seat in front of you |
| Weight limit | None, but you must lift the bag into the bin yourself |
| Cost | Carry-on and personal item are both free |
| If your bag is too big | Gate check, and checked bags now start at $35 on standard fares |
Source: Southwest's official carryon and personal item policy, verified July 2026.
What Southwest's carry-on size limit actually covers
Southwest allows one carry-on bag up to 24 × 16 × 10 inches, which is the most generous limit of any major U.S. airline. The measurement covers the entire bag, so wheels, telescoping handles, and exterior pockets all count. A bag marketed as a "22-inch carry-on" often measures 23 inches or more once you include the wheels, which is why you should measure the real thing instead of trusting the product name.
Personal item rules
Your personal item goes under the seat in front of you. Southwest doesn't publish exact dimensions for it, but bags around 16 × 13 × 8 inches fit under most seats without a fight. A backpack, purse, laptop bag, or briefcase all qualify, and a pet carrier counts as either your carry-on or your personal item, not as a bonus third bag.
There's no weight limit, with one catch
Southwest sets no weight limit on carry-ons. The practical rule is that you have to lift the bag into the overhead bin on your own. If you need a second person to get it up there, it belongs in the cargo hold.
How strict is Southwest about carry-on size in 2026?
Southwest is stricter than it used to be. For years the airline barely looked at carry-on dimensions, and travelers got comfortable bringing bags an inch or two over.
That era is ending. Recent traveler reports describe gate agents actively scanning boarding areas, pulling borderline bags, and using the metal sizer bins that used to sit ignored next to the podium.
Three things get bags flagged consistently:
- An expandable bag left expanded. If the expansion zipper is open and the bag won't zip down to its compliant size, agents check it. Expanded bags are the most commonly reported trigger.
- Front pockets and pouches that stick out. A stuffed exterior pocket pushes an otherwise legal bag past the 10-inch depth. Agents have learned to spot the bulge.
- Visible overstuffing. A bag straining at the zippers invites a trip to the sizer even when it technically fits.
Enforcement still varies by airport. Some travelers report every carry-on on their flight being checked against the sizer, while others walk past untouched. Treat strict enforcement as the default and you'll never be the person unpacking at the gate.
Measure it like a gate agent
Before you leave for the airport, run this check on your packed bag:
- Pack the bag completely, then measure it. An empty bag lies.
- Include the wheels and the retracted handle in your height measurement.
- Zip the expansion gusset closed. Fly with it closed.
- Flatten or empty protruding front pockets.
- Compare your numbers to 24 × 16 × 10. If you're within an inch of any limit, assume the sizer decides.
What happens if your bag is too big (and what it costs now)
If your bag fails the sizer, it gets gate checked into the cargo hold and you pick it up at baggage claim. That used to be a minor inconvenience because Southwest checked two bags free for everyone. That safety net is gone.
Since May 2025, standard fares pay $35 for a first checked bag and $45 for a second. Travelers have reported paying that $35 on the spot at the gate for a bag that measured barely over the limit. A few groups still check bags free:
- Rapid Rewards credit cardmembers get one free checked bag
- A-List members get one free checked bag
- A-List Preferred members get two free checked bags
- Choice Extra fares include free checked bags
- Active-duty military with valid ID check bags free
If your bag is borderline, the fix costs nothing: measure it packed, fly with the expansion zipped, and move overflow into your personal item.
If your bag is compliant but the bin is full, that's a different problem. Southwest flies both the Boeing 737-700 and 737-800, and the older 700s have noticeably smaller overhead bins. A bag that meets the size limit can still fail to fit on an older plane, so board when your group is called instead of hanging back. Bags gate checked for space, rather than for size, are not charged.
Southwest carry-on size vs other airlines
Southwest is the outlier among U.S. carriers, in a good way.
| Airline | Carry-on size limit | Source |
|---|---|---|
| Southwest | 24 × 16 × 10 inches | Southwest carryon policy |
| Delta | 22 × 14 × 9 inches | Delta carry-on baggage |
| American Airlines | 22 × 14 × 9 inches | American carry-on baggage |
| United Airlines | 22 × 14 × 9 inches | United carry-on bags |
All four airlines count wheels and handles toward the limit.
That extra allowance cuts both ways. A bag built to max out Southwest's limit is a Southwest-only bag, and the moment you book Delta or United it becomes a checked bag with a fee attached.
There's one more reason to think twice before buying to the 24-inch limit: Southwest has reportedly discussed aligning its carry-on size with the 22-inch industry standard so bags transfer cleanly to its international partners. Nothing is announced, but a 22 × 14 × 9 bag is the future-proof buy. It fits every major U.S. airline today and keeps fitting Southwest no matter what the policy does.
Carry-on bags that fit Southwest's limits with room to spare
One nuance worth knowing before you pick a bag: soft-sided luggage compresses. If a softside bag is snug in the sizer, you can squash it in. A hard shell is a pass-or-fail test with no give, so hardshell buyers should want more margin on paper.
Every bag below fits Southwest's 24 × 16 × 10 limit with inches to spare, and the dimensions listed include wheels and handles.
| Bag | Dimensions | Weight | Fits 22 × 14 × 9 standard? | Price |
|---|---|---|---|---|
| Lares Carry On (softside) | 21.75 × 13 × 8.5 in | 6.9 lbs | Yes, every major airline | $109.99 |
| Silverwood Softside Carry On | 20.75 × 14 × 9 in | 6.48 lbs | Yes, every major airline | $129.99 |
| Pagosa Carry On (hardside) | 22 × 14 × 9.25 in | 7.26 lbs | Within a quarter inch, unexpanded | $109.99 |
| Markham Carry-On (hardside) | 21.75 × 14.5 × 9.5 in | 7.4 lbs | Southwest yes; tighter elsewhere | $199.99 |
The Lares Carry On is the pick if you want maximum sizer margin. At 21.75 × 13 × 8.5 inches and 6.9 pounds, it clears every airline's limit with room left over, and the soft shell gives you that compression insurance on a crowded flight. The honest trade-off is that a soft shell protects fragile contents less than a hard one.
The Silverwood Softside Carry-On is the lightest bag here at 6.48 pounds, which matters when you're lifting it into a 737-700's smaller bin. It gives up some packing capacity to a maxed-out 24-inch bag, and that's the price of a bag that never argues with a sizer.
The Pagosa Carry-On is the value hardside at $109.99, with a USB charging port, a TSA-approved lock, and a polycarbonate shell. Its 9.25-inch depth is measured unexpanded, so treat the expansion zipper as a one-way trip for the flight home and fly with it closed. Hard shells don't compress, which makes that zipped-closed habit non-negotiable.
The Markham Carry-On is the upgrade pick at $199.99, with Hinomoto wheels, YKK zippers, a USB port, and a TSA lock. It's built for people who fly Southwest often enough to feel the wheel quality. At 14.5 × 9.5 inches in width and depth it has less margin on other airlines' sizers, so it's the choice for Southwest loyalists rather than airline-hoppers.
Every current option is in the carry-on collection, with dimensions listed on each product page. If you want the full decision framework beyond Southwest compliance, our guide on how to choose luggage covers shells, wheels, and zippers in depth. And if a Southwest flight is how your last bag died, that's the business we know from the other side: Traveler's Choice supplies replacement luggage for eight U.S. airlines, including Southwest.
Packing tips for Southwest's overhead bins
A compliant bag can still be a badly packed one. A few habits keep you out of trouble:
- Measure the bag after packing, not before. Contents change the shape of a softside bag by half an inch or more.
- Zip the expansion closed before you get in line. Expanded bags are the number one gate-check trigger.
- Use packing cubes to compress clothes instead of expanding the bag. Our packing cubes guide shows the folding method that saves the most depth.
- Let the personal item carry your overflow. It rides under the seat, where nobody measures.
- Check the TSA's prohibited items list before you pack, since security rules apply on top of Southwest's size rules.
- Southwest now uses assigned seating on all flights, but bins still fill from the front. Board when your group is called.
FAQ
Can a 24-inch suitcase be a carry-on on Southwest?
Usually it can't. Most bags sold as "24-inch" measure 26 inches or more once wheels and handles count, which puts them past the limit. Check the true overall dimensions, and if they genuinely fit within 24 × 16 × 10, the bag qualifies.
What is Southwest's carry-on size in centimeters?
The limit is 61 × 41 × 25 cm, including wheels and handles.
Does Southwest charge for carry-on bags?
No, one carry-on and one personal item fly free on every fare. The fees added in 2025 apply to checked bags, not cabin bags.
What are the new bag rules for Southwest in 2026?
The carry-on size limit is unchanged at 24 × 16 × 10 inches. What's new is paid checked bags on standard fares, assigned seating on all flights, and noticeably tighter enforcement of carry-on size at the gate.
Can I bring a backpack as a carry-on on Southwest?
Yes, a backpack can be your carry-on if it fits the overhead bin limit, or your personal item if it fits under the seat. Many travelers pair a compliant roller bag with a backpack and check nothing.
The bottom line
Southwest gives you the biggest carry-on allowance in the country at 24 × 16 × 10 inches, and in 2026 it actually measures. Fly with the expansion zipped, measure your packed bag with wheels included, and you'll walk past the sizer without a second thought. If you're replacing a bag anyway, buy to the 22 × 14 × 9 standard instead of the Southwest maximum, because that bag works on every airline you'll ever book.
