Everything You Need to Know About Southwest's Carry-On Size Allowance

Packing for your trip can be tricky, especially when you are not sure if your bag will actually fit in the overhead bin. If you are flying with Southwest, understanding the Southwest carry-on size and what’s included in it can save you from the last-minute repacking panic at the gate. The good news? Southwest keeps things simple and pretty traveler-friendly compared to many other airlines. So, whether you are a frequent flyer or planning your first Southwest trip, here’s everything you need to know to pack smart and breeze through boarding without any baggage problems.

Read our blog to know more about this carry-on aspect of the Southwest Airlines baggage policy for a smooth experience.

What is the Southwest Carry-on Size Limit?

Southwest Airlines allows one carry-on bag and one personal item per passenger. The official carry-on luggage size Southwest allows is 24 x 16 x 10 inches (61 x 41 x 25 cm), including handles and wheels. Your bag needs to fit either in the overhead bin or under the seat in front of you, depending on the type of item.

Your personal item (like a backpack, laptop bag, or purse) should fit under the seat and must not exceed 16.25 x 13.5 x 8 inches (41 x 34 x 20 cm).

So, if you’re wondering whether it's your favorite suitcase or duffel, grab a tape measure and check it before you pack!

What About Southwest Carry-On Weight Limits?

Here’s some good news — Southwest does not have a strict weight limit for carry-on baggage. As long as you can lift your bag into the overhead bin without help, you’re good to go. That’s a big win for travelers who like to squeeze in those extra shoes or electronics without worrying about tipping the scales.

However, it’s always smart to pack light to make your airport experience smoother and avoid the struggle of hauling a heavy bag through the terminal.

Before you pack, check Book Southwest Flights Tickets Online to see fare types that include carry-on and free checked bags

Understanding Southwest Airlines Carry-On Rules. 

To make your journey hassle-free, here are a few key rules to keep in mind:

• You can bring 1 carry-on bag + 1 personal item onboard for free.
• All items must fit in approved spaces (overhead bin or under the seat).
• Liquids must comply with the TSA’s 3-1-1 rule — that means containers of 3.4 ounces (100 ml) or less, all placed in a 1-quart clear plastic bag.
• Sharp objects, flammable materials, and oversized liquids are not allowed in carry-ons.
• Duty-free liquids purchased after security screening are permitted, as long as they remain sealed in their original bag with the receipt.

These Southwest Airlines carry-on rules are in line with TSA regulations, so following them ensures you breeze through security without any trouble.

Pro Packing Tips for Southwest Flyers

• Opt for soft-sided luggage: It’s more flexible when fitting into tight overhead bins.
• Keep essentials handy: Medications, chargers, travel documents, and valuables should go in your personal item for easy access.
• Use packing cubes: They help you stay organized and make the most of your bag’s space.
• Check the plane type: Smaller aircraft may have tighter bin spaces, so pack accordingly.

And remember — Southwest doesn’t assign seats in advance, so boarding early (via EarlyBird Check-In or A-List status) can help you find better overhead bin space for your carry-on.

Want to know when to book to get better bag inclusions? See Best Time to Book Southwest Flights.

What Makes Southwest’s Policy Traveler-Friendly?

One of the best aspects of Southwest Airlines' baggage policy is that it’s transparent — no hidden fees or confusing terms. Now, from May 28, 2025, Southwest Airlines allows free checked bags to only those with A-list Preferred Status, Business Select Fares, and Southwest credit cards. 

So, if you pack strategically, you can easily travel with just your carry-on and avoid any baggage lines altogether.

For multi-leg travel, our Southwest Multi-City Booking Guide shows how to combine routes without violating carry-on rules.

Final Thoughts

Southwest’s baggage rules are designed with travelers in mind — simple, clear, and generous. By understanding the Southwest carry-on size and the basic rules, you can pack efficiently, board smoothly, and start your trip stress-free. Whether you’re heading out for a quick business trip or a weekend getaway, knowing what fits and what doesn’t makes all the difference in how easily your journey begins. So, book your Southwest Airlines flight with ExperianAirfare now. 

Need to compare international baggage rules? Check out TAP Air Portugal Baggage Allowance.