Packing for a Southwest flight gets much easier once you know exactly what fits in the cabin. If your bag is too large, you could end up checking it at the airport instead of taking it onboard.
So, what is the Southwest Airlines carry-on size? Southwest Airlines allows one carry-on bag with dimensions of up to 24 x 16 x 10 inches including the wheels, handles, and attachments. You can also bring one personal item that fits under the seat in front of you.
That covers the basic rule, but there is more to keep in mind before you start packing. If you’re planning to book cheap flights to India, here’s what Southwest allows in your carry-on, what belongs under the seat, and which items need extra attention at security.
Southwest Airlines Carry-On Size and Dimensions
The Southwest Airlines carry-on size is:
- Length – 24 inches
- Width – 16 inches
- Height – 10 inches
Southwest Airlines measures the entire bag, so wheels, handles, pockets, and other attachments count toward the limit. The airline gives roller bags and small suitcases as examples of standard carry-on bags. Your standard carry-on goes in the overhead bin. Before leaving for the airport, measure the bag from its outermost points rather than relying only on the manufacturer’s listed suitcase dimensions.
Southwest Airlines Carry-On Weight Limit
Southwest has no stated weight limit for carry-on luggage. The main number to remember is the 24 x 16 x 10-inch Southwest Airlines carry-on size limit.
That doesn’t mean you should fill your suitcase until it’s difficult to lift. You need to handle the bag easily and place it safely in the overhead bin. If your trip includes a partner airline, you must check its baggage rules too, since its carry-on rules may differ.
Southwest Airlines Personal Item Rules
Along with your carry-on, Southwest lets you bring one personal item onboard including a purse or crossbody bag, briefcase, laptop case, backpack, small camera, blanket, or pillow. It goes under the seat in front of you.
A neck pillow doesn’t count toward your carry-on allowance. Southwest also doesn’t give a fixed numerical size for personal items. However, your personal item goes beneath the seat in front of you.
Using a backpack? Don’t overfill it. Once it becomes too bulky to slide under the seat, you have a problem. Keep the things you’ll want during the flight in your personal item, such as:
- Passport and travel documents
- Wallet
- Phone and charger
- Medication
- Headphones
- Small electronics
- Important valuables
Carry-On and Personal Item: What You Can Bring
Southwest allows each passenger to bring one carry-on bag and one personal item. The carry-on is stored in the overhead bin, while the personal item should fit beneath the seat in front of you.
A simple setup is a 24 x 16 x 10 inch roller bag as your carry-on and a backpack with your laptop, travel documents, medication, and other essentials as your personal item.
Bringing an extra carry-on or personal item? You’ll need to check the additional bag at the ticket counter before heading to the gate. Your purse or backpack counts as your personal item, so you don’t get a second personal-item allowance. Think of it as two cabin bags total: one overhead and one under the seat.
Southwest Airlines Liquids Rules
Packing liquids in your Southwest carry-on? Keep the TSA 3-1-1 liquids rule in mind.
Each container must hold 3.4 ounces (100 ml) or less
All your containers need to fit inside one quart-size clear plastic bag
Each passenger gets one liquids bag.
Keep the bag within easy reach at the airport. You’ll need to take it out during security screening. Shampoo, conditioner, toothpaste, lotion, liquid makeup, sunscreen, perfume, and hair products all follow the same size limit.
Got a larger container? It exceeds the standard Southwest Airlines carry-on liquids limit, so pack it in your checked baggage instead.
Traveling With Medication on Southwest Airlines
Keep your prescription and medication in your carry-on or personal item so you have it with you during the trip. If your carry-on gets checked because of limited overhead space, take your medication out and keep it with you.
An overnight connection needs a little extra attention. Checked bags stay with the airline during an overnight connection, so you won’t have access to medication packed inside them. Keep any medication and other essentials you need during the journey in your cabin baggage instead.
Traveling with syringes, needles, or other medical supplies? Keep them packed with the medication they’re associated with. Make sure any sharp items are properly covered and secured as loose sharps can cause injuries during baggage handling.
Electronics and Batteries in Your Carry-On
Keep your laptop, tablet, phone, camera, e-reader, and other personal electronics in your Southwest Airlines carry-on or personal item. That keeps your devices close and makes them easier to use during the flight. Southwest allows each customer to bring up to 15 portable electronic devices.
Power banks have their own rules. As of April 20, 2026, Southwest allows each customer to bring one power bank, with a maximum capacity of 100 watt-hours. It must stay in the cabin, not in checked baggage. Place it beneath the seat in front of you instead of using the overhead bin. When you use a power bank during the flight, keep it visible rather than tucked inside your bag.
Spare lithium batteries also need to stay in your cabin baggage instead of checked luggage. Protect the battery terminals so they don’t come into contact with other objects and cause a short circuit.
Restricted and Prohibited Items on Southwest Airlines
On a Southwest Airlines flight, you don’t have to carry everything in your carry-on. Some items are restricted or prohibited because of TSA and aviation safety rules. Southwest specifically lists items such as fireworks, flammable liquids, certain aerosols, paints, and oxygen cylinders as prohibited unless a specific regulatory exception applies.
Items that need special attention
Pay extra attention when packing:
- Power banks and spare lithium batteries
- E-cigarettes and vaping devices
- Lighters and matches
- Sharp objects
- Aerosols
- Flammable materials
- Fireworks
- Self defense sprays
Keep e-cigarettes and vaping devices in your cabin baggage rather than checked luggage. You also cannot use or charge these devices during the flight. Pepper spray and mace are not allowed in your carry-on, checked baggage, or on your person.
Southwest Airlines Pet Rules
Flying with a pet? The pet carrier counts as either your personal item or your carry-on bag. Southwest allows small cats and dogs in approved carriers on eligible flights. The carrier needs to fit under the seat, and your pet must stay inside it in the gate area, during boarding and deplaning, and throughout the flight.
Southwest accepts pet carriers in these sizes:
- Southwest pet carrier – 15 x 10 x 10 inches
- Other approved pet carriers – Up to 18 x 10.5 x 10 inches
The carrier must also be leak-proof and properly ventilated.
What Happens If Your Carry-On Is Too Large?
If your bag goes over the 24 x 16 x 10-inch Southwest Airlines carry-on size limit, don’t rely on how close it looks to the maximum. Measure the full bag at home, including the wheels, handles, and attachments. If it doesn’t meet the size limit for cabin storage, you’ll need to check the bag at the ticket counter before heading to the departure gate.
Final Thoughts
Before packing for your Southwest flight, remember the 24 x 16 x 10-inch carry-on limit. Southwest counts the wheels, handles, and attachments in those measurements. You can also bring one personal item under the seat.
If another airline is part of your itinerary, check its baggage allowance separately. Its carry-on rules may not match Southwest’s.
Travelers planning to travel between US and India can check TripBeam for affordable international flights that suit your travel dates and budget.
FAQs
Q1) What are the exact size limits for Southwest carry-on bags and personal items?
A) The Southwest Airlines carry-on size limit is 24 x 16 x 10 inches, including the wheels, handles, and attachments. The bag must fit in the overhead bin. A personal item can measure up to 16.25 x 13.5 x 8 inches and must fit completely under the seat in front of you.
Q2) Does Southwest weigh carry-on bags at the gate?
A) No, Southwest does not have a weight limit for carry-on bags or personal items. However, your bag must stay within the airline’s size limits, and you must be able to lift it into the overhead bin yourself without assistance from the flight crew.
Q3) What items do not count toward Southwest’s carry-on allowance?
A) Several items do not count toward Southwest’s one carry-on bag and one personal item allowance. These include outerwear, umbrellas, food and drinks purchased after security, mobility aids, CPAP machines, child safety seats, strollers, breast pumps, and diaper bags used for infant care.
Q4) Can I bring a guitar or musical instrument as a carry-on on Southwest?
A) Yes. A small musical instrument, such as a guitar or violin, can count as your one carry-on item if it fits in the overhead bin or under the seat. Overhead bin space is available on a first-come, first-served basis.
Q5) If my carry-on gets gate-checked, what must I remove immediately?
A) If your carry-on is gate-checked, remove power banks, spare lithium batteries, prescription medications, essential electronics, keys, passports, and valuable items before handing over the bag. Keep these items with you in the cabin.
Q6) Where must lithium power banks be stored on Southwest flights?
A) Power banks and spare lithium-ion batteries must stay in the passenger cabin, not checked baggage. Keep power banks in your personal item under the seat, not in the overhead bin, and do not charge them using in-seat power outlets.