Southwest's carry-on size limits

Southwest allows one carry-on bag that fits in the overhead bin, and it must be no larger than 24 inches long, 16 inches wide, and 10 inches deep. The airline measures these dimensions at the widest points of your bag. If your bag is larger than these measurements, you will have to check it at the gate, and Southwest will charge you a fee.

A standard rolling carry-on suitcase designed for airline travel usually fits within these limits. Soft-sided bags are easier to squeeze into tight overhead spaces than hard-shell luggage, so if your bag is close to the maximum size, a flexible material gives you a better chance of fitting it overhead.

Southwest also allows one personal item free of charge — a purse, backpack, laptop bag, or small daypack. This item must fit under the seat in front of you. There is no official size limit for personal items, but if it is so large that it does not fit under a seat, a gate agent may ask you to check it.

Key Takeaways

  • Your carry-on bag cannot exceed 24 inches long, 16 inches wide, and 10 inches deep, or Southwest will check it at the gate for a fee.
  • Soft-sided bags compress more easily than hard-shell cases and are more likely to fit in overhead bins when the cabin is full.
  • You can bring one personal item (purse, backpack, laptop bag) for free as long as it fits under the seat in front of you.
  • Gate agents measure bags that look oversized, so packing efficiently and choosing the right bag style matters more than the exact dimensions.

How Southwest measures your bag

Southwest does not weigh carry-on bags — only checked luggage has weight restrictions. However, gate agents do visually inspect carry-on bags and may measure them if they appear to exceed the 24 x 16 x 10 inch limit. The measurement is taken at the bag's bulkiest points, including wheels, handles, and any pockets that stick out.

If your bag does not fit in the overhead bin during boarding, a gate agent will ask you to check it. You will not pay a fee if this happens during the boarding process itself, but if you try to bring an oversized bag to the gate and it is rejected before you board, you may face a checked bag fee. The best approach is to pack light and choose a bag that is clearly within the size range.

Checked bag fees and when your carry-on becomes checked

Southwest's first checked bag is free, and the second checked bag is also free — a policy that sets Southwest apart from most other airlines. However, if your carry-on is too large and must be checked at the gate, it counts as a checked bag. If you already have two bags checked, a third bag (your oversized carry-on) will incur a fee.

Bags checked at the gate are treated the same as bags checked at the ticket counter. They must weigh no more than 50 pounds and measure no more than 62 inches (length plus width plus depth). Most carry-on-sized bags easily meet these checked bag limits, so size is rarely a problem once a bag is checked — only the number of bags matters.

What fits in a standard carry-on

A 24 x 16 x 10 inch bag holds enough for a weekend trip or a week of light packing. Rolling suitcases in this size typically have a capacity of 22 to 40 liters, depending on the brand and design. You can fit several days' worth of clothing, toiletries, a laptop, and a change of shoes in a properly packed carry-on.

Hard-shell suitcases offer better protection for fragile items but take up more space because they do not compress. Soft-sided bags allow you to squeeze extra items into corners and crevices, which is useful when you are traveling with a full load. Hybrid bags with a soft exterior and rigid frame offer a middle ground.

Packing tips to stay within size limits

Roll your clothes instead of folding them — rolling saves space and reduces wrinkles. Place heavier items like shoes at the bottom of your bag and lighter items on top. Use packing cubes or compression bags to organize clothing and create more room for other items.

Keep your personal item small enough to fit comfortably under the seat. A backpack or crossbody bag works better than a large tote for this purpose. If you are traveling with a laptop, consider a bag with a dedicated laptop compartment so you do not waste space trying to fit it alongside clothing.

Avoid overstuffing your bag to the point that the seams bulge or the bag cannot close properly. A bag that looks obviously oversized will be flagged by gate agents, even if it technically fits the dimensions. Packing efficiently and leaving a little room for compression is the safest approach.

Bags that typically exceed Southwest's limits

Large rolling suitcases designed for checked baggage — often labeled as 28-inch or larger — will not fit in a carry-on space. Duffel bags and weekender bags can be deceptive because they look soft and flexible, but many are wider or deeper than 16 or 10 inches. Always check the manufacturer's dimensions before buying a new bag.

Backpacks larger than 40 liters often exceed the carry-on size limit, especially if they have external pockets or straps that add bulk. Messenger bags and laptop bags vary widely in size, so measure yours before your trip. If you are unsure whether your bag fits, bring it to the airport early enough to ask a gate agent before you board.

What to do if your bag is too large

If you arrive at the gate and your bag is flagged as oversized, you have a few options. You can check the bag if you have not already checked two bags — it will travel in the cargo hold and arrive with your flight. You can also remove items from your bag and place them in your personal item or ask a travel companion to hold them.

If you are checking the bag, make sure it is locked and that you remove any fragile items or valuables. Checked bags can shift during loading, so pack accordingly. If you frequently travel with a bag that is close to the size limit, consider buying a smaller carry-on suitcase to avoid this problem on future trips.

Frequently Asked Questions

Can I bring a roller bag and a backpack as my carry-on?

No. You can bring one carry-on bag and one personal item. The roller bag counts as your carry-on, and the backpack would be your personal item. Both must fit in the overhead bin and under the seat, respectively. If you try to bring two full-sized bags, one will be checked.

Do I need to remove my carry-on from the overhead bin when I land?

No. You can leave your bag in the overhead bin until the plane reaches the gate and the captain turns off the seatbelt sign. Overhead bins are part of the aircraft, so your bag travels with the plane. Remove it when you are ready to exit.

What if my bag has wheels that add extra inches?

Wheels are included in the measurement. A bag that is 24 inches long with wheels is still 24 inches long. If your bag's wheels, handle, or pockets make it exceed the size limit, it will be considered oversized. Soft-sided bags with wheels often compress enough to fit, but hard-shell bags with protruding wheels can be problematic.

Can I bring a car seat or stroller as a carry-on?

Car seats and strollers are not counted as carry-on bags. You can bring a car seat and a stroller in addition to your carry-on and personal item. However, strollers are usually checked at the gate and returned to you when you land. Ask a gate agent about the specific policy for your flight.

Is there a weight limit for carry-on bags on Southwest?

Southwest does not enforce a weight limit for carry-on bags. The only weight restrictions explore to checked bags, which must weigh 50 pounds or less. However, if your carry-on is so heavy that you cannot safely lift it into the overhead bin, a gate agent may ask you to check it.