Travelers flying with Southwest Airlines often want to know exactly how large their carry-on bag can be before arriving at the airport. Understanding the Southwest airline carry on size requirements can help you choose the right suitcase, avoid last-minute problems, and make boarding easier. Southwest currently allows each ticketed passenger to bring one standard carry-on bag and one smaller personal item at no additional charge.

Southwest Airline Carry On Size Requirements

The standard Southwest airline carry on size is 24 x 16 x 10 inches (length × width × height), including the bag’s exterior dimensions. Southwest lists the measurement in a different order as 10 x 16 x 24 inches, but the maximum dimensions are the same.

A qualifying carry-on can generally be a roller suitcase, garment bag, tote-style bag, or another suitable piece of luggage. It must be capable of being stored in the aircraft’s overhead compartment.

Before traveling, measure your luggage from the outside rather than relying only on the manufacturer’s advertised dimensions. Wheels, handles, pockets, and other external components can affect the overall size.

What Is the Southwest Personal Item Size?

In addition to a standard carry-on, Southwest permits one smaller personal item. Examples include a purse, briefcase, laptop case, small backpack, or small camera bag. The item needs to be capable of being stored under the seat or in an overhead compartment.

For travelers, this means a practical combination can be a rolling suitcase in the overhead bin plus a small backpack or laptop bag under the seat. Keeping your personal item compact can make it easier to store and retrieve during the flight.

Does Southwest Charge for a Carry-On Bag?

Southwest’s current fee information states that carry-on bags and personal items are free for ticketed passengers. This applies separately from the airline’s checked-baggage rules.

However, checked-bag fees can depend on the fare, booking date, route, and other eligibility factors. For U.S. mainland travel booked or changed on or after April 9, 2026, Southwest lists checked-bag fees for several fares while maintaining free carry-on and personal items.

Therefore, passengers should distinguish between a carry-on bag that goes into the cabin and a checked bag that is handed over at the airport.

How to Measure a Southwest Carry-On Bag

Measuring your suitcase before leaving home is one of the easiest ways to avoid baggage problems. Place the bag on a flat surface and measure its maximum exterior length, width, and height.

Remember that the Southwest limit includes the outside dimensions of the bag. A suitcase advertised as being 24 inches long may have slightly different overall dimensions once wheels and handles are included.

If your suitcase is close to the maximum size, check all three dimensions carefully. A bag that exceeds one measurement may not fit the airline’s sizing requirements even if its total volume seems reasonable.

What Happens If Your Carry-On Is Too Large?

Southwest Airline Carry On Size states that carry-on baggage must be stored underneath a seat or in an overhead bin, and the airline retains discretion over whether baggage can be accepted in the passenger cabin based on size and other factors.

If a bag cannot be accommodated as a cabin carry-on, the airline may require it to be handled under a different baggage arrangement. That can potentially result in additional charges depending on the circumstances and applicable baggage rules.

Southwest Airline Carry On Size that reason, travelers should not assume that an oversized suitcase will automatically be accepted simply because it can physically be brought to the gate.

Tips for Choosing a Southwest Carry-On

When purchasing luggage for Southwest, look for a suitcase whose total exterior dimensions stay within 24 x 16 x 10 inches. Soft-sided luggage can sometimes provide useful flexibility, but it still needs to comply with the applicable size requirements when packed.

Avoid filling expandable luggage beyond its intended dimensions. An expanded suitcase can become larger than the permitted carry-on size.

It is also useful to keep important items such as medication, identification, electronics, and valuables in an easily accessible personal item. This can make security screening and boarding more convenient.

Special Items and Carry-On Rules

Some items have specific Southwest policies. For example, musical instruments that meet the carry-on size limit can be brought onboard as a carry-on when space is available. Southwest also has separate rules for instruments that exceed the standard carry-on dimensions but can fit safely in an overhead bin or under a seat.

Passengers traveling with children may also have additional allowances. Southwest says an FAA-approved child restraint system used during the flight can be carried on without counting toward the normal carry-on limit.

Travelers with pets should also check the airline’s separate pet-carrier requirements because an approved pet carrier must fit under the seat and has its own size limitations.

Southwest Airline Carry On Size FAQs

1. What is the Southwest airline carry on size?

The maximum standard carry-on dimensions are southwest airline carry on size, including the exterior dimensions of the bag.

2. Can I bring a backpack as a personal item?

Yes. Southwest lists a backpack as an example of a personal-type item, provided it can be properly stowed under a seat or in an overhead compartment.

3. Is a carry-on free on Southwest Airlines?

Yes. Southwest’s current baggage information states that ticketed passengers can bring one carry-on bag and one personal item without a carry-on charge.

4. Do wheels count toward carry-on dimensions?

Yes. Travelers should measure the complete exterior dimensions of their luggage, including components such as wheels and handles,Southwest Airline Carry On Size when determining whether the suitcase fits the stated limit.

5. Can I bring a laptop bag and a carry-on suitcase?

Southwest Airline Carry On Size. A laptop case can qualify as a personal item, while a standard-size suitcase can serve as the carry-on, provided both items meet Southwest’s applicable storage requirements.

6. Can a musical instrument be a carry-on?

Yes. Southwest states that an instrument and its case can be carried on when it meets the 24 x 16 x 10-inch carry-on limit and space is available.

7. What should I do if my suitcase is larger than the limit?

Measure the suitcase carefully before traveling. If it exceeds the published carry-on dimensions, review Southwest’s baggage rules for the applicable options rather than assuming it will be accepted in the cabin.

Conclusion

Knowing the Southwest airline carry on size before your trip can make airport travel much easier. The current standard maximum is 24 x 16 x 10 inches, and passengers can also bring one smaller personal item that can be properly stowed.