The Southwest carry-on dimensions are 24 x 16 x 10 inches. You also get one personal item. Both are free on every fare.

This guide covers size limits in inches and cm, personal item size, weight, special items, and what happens at the gate. Rules change, so confirm key details on southwest.com before you fly.

Southwest Carry-On Dimensions and Size Limits

What size is a Southwest carry-on? The limit is 24 inches long, 16 inches wide, and 10 inches deep. That is about 61 x 41 x 25 cm. Wheels, handles, and attachments count.

The carry-on goes in the overhead bin. The personal item goes under the seat in front of you.

Item	Max size (in)	Max size (cm)	Where it goes	Cost
Carry-on bag	24 x 16 x 10	61 x 41 x 25	Overhead bin	Free
Personal item	16.25 x 13.5 x 8†	41 x 34 x 20†	Under the seat	Free
Weight limit	None published	None published	You must lift it	–

†Commonly listed size. Southwest’s own help page does not give a personal item size.

Add the three carry-on sides and you get 50 linear inches (127 cm). Many airlines cap carry-ons at 22 inches long. Southwest allows 24, so it is a roomy limit.

How do you measure a carry-on? Measure the packed bag, not the empty one. Include the wheels and the handle base. Check the depth last. A full front pocket can push a bag past 10 inches.

Soft-sided bags help. They squeeze into a sizer bin more easily than a hard shell.

Southwest Personal Item Size and What Counts

What counts as a personal item? A purse, backpack, laptop bag, briefcase, or small camera bag. The item must fit fully under the seat in front of you.

Some things do not count toward your two items. Examples include neck pillows, child car seats, assistive and mobility devices, outer coats, canes, umbrellas, and food in disposable packaging.

A pet carrier uses one of your two slots. A pet fee also applies. The amount is listed at $125 on mainland US flights in some sources and differs on others, so confirm it when you book. The carrier size is often listed as 18.5 x 8.5 x 13.5 inches.

Bag type	Usually fits under the seat?
Small or school-size backpack	Yes
Purse, laptop bag, or briefcase	Yes
Tote bag (not overstuffed)	Yes
Weekender duffel	Borderline. Squeeze it flat first.
Rolling carry-on	No. It belongs in the overhead bin.

Seat type matters too. Bulkhead and some aisle seats can offer less under-seat room. A softer bag adapts better.

Just as choosing the right carry-on dimensions helps you maximize travel space, understanding container sizes is essential for storing and transporting larger quantities of liquids and materials. Explore standard IBC tote sizes and capacities to learn about their dimensions, volume, and practical uses for storage and transportation.

Southwest Carry-On Rules, Weight, and Special Items

Is there a weight limit? Southwest does not publish one for carry-ons. Still, you must lift the bag into the bin without help.

Can you bring a power bank? Yes, with limits. The FAA says spare lithium batteries and power banks must travel in your carry-on only. Batteries are capped at 100 watt-hours each unless the airline approves more. See the FAA lithium battery rules.

Southwest added its own rule on April 20, 2026. Each passenger may carry one lithium portable charger. It cannot go in the overhead bin, and you cannot recharge it from in-seat power, per TravelPulse.

Liquids follow the TSA rule: containers of 3.4 oz (100 ml) or less, all in one quart-size bag. Check the TSA “What Can I Bring?” tool for any item you are unsure about.

• Strollers and car seats: one of each is checked free per ticketed child.
• Medical items: mobility aids and screened medications do not count as carry-ons.
• Musical instruments: small ones can ride as a carry-on. Large ones may need a purchased seat or must be checked.

Checked bags are a different story. Standard fares booked on or after May 28, 2025 pay $35 for the first bag and $45 for the second, per The Points Guy. Free bags depend on your fare and status. Rapid Rewards A-List members and credit cardholders get a free first bag. A-List Preferred members get two. Active-duty military with ID also qualify.

Fees change often. Check your own fare before you pack.

What If Your Southwest Carry-On Is Too Big?

Gate agents can check bags with a metal sizer bin. Southwest does not publish a tolerance. Reports say enforcement varies by airport and can be strict.

A bag that does not fit gets gate checked and rides in the cargo hold. Some travelers report paying the checked-bag fee at the gate. Bags checked only because the bins are full are not charged.

If you must gate check, take out your power bank and spare batteries first. The FAA says they must stay with you in the cabin.

How can you shrink a bag that is too big?

• Remove bulky items and move them to your personal item.
• Switch to a soft-sided bag.
• Wear your heaviest shoes and jacket.
• Use packing cubes and compress the bag flat.
• If it still will not fit, pay to check it online instead of at the gate.

A quick pre-flight check helps. Measure the packed bag, test the liquids bag, pack batteries in your carry-on, and read the rules for any partner airline on your trip.

Southwest Carry-On FAQs

How strict is Southwest with carry-on size?

Southwest publishes no tolerance. Reports say agents use sizer bins, and enforcement varies by airport. Treat 24 x 16 x 10 inches as a hard limit, and measure your bag while it is packed.

Can a 24 inch luggage be a carry-on Southwest?

Yes, if the whole bag, including wheels and handle, fits within 24 x 16 x 10 inches. Many 24-inch suitcases are deeper than 10 inches, so check the depth before you fly.

Does Southwest allow 1 or 2 carry-ons?

You get one carry-on bag and one personal item. That is two items, and both are free. The carry-on goes in the overhead bin, and the personal item goes under the seat.

What are the new carry-on rules for 2026?

The carry-on size limit has not changed. New rules include one lithium portable charger per passenger since April 20, 2026, with none in the overhead bin. Checked bag fees of $35 and $45 also apply on standard fares booked since May 28, 2025.

What happens if my carry-on is 1 inch too big?

Southwest lists no tolerance. An agent can gate check the bag, and a checked-bag fee may apply. Take out batteries and power banks first, since they must stay in the cabin.

What three new items did TSA ban?

Reports named three hair-tool items for checked bags: gas-powered cordless curling irons or flat irons, butane-fueled ones, and gas refill cartridges. Those reports cite FAA hazmat rules, not a dated TSA announcement, and another review found no new TSA bans. Check the TSA “What Can I Bring?” tool before you pack.

Conclusion

The Southwest carry-on dimensions are 24 x 16 x 10 inches, plus a free personal item. Measure your packed bag, keep power banks in the cabin, and confirm current rules on southwest.com.