Southwest Carry-On Size Requirements 2026
Understanding Southwest's carry-on size requirements helps you pack smart and avoid gate-checking your bag. This comprehensive guide covers exact dimensions, what counts as a personal item, and tips for maximizing your free carry-on allowance.
Official Carry-On Size Limits
Carry-On Bag
10 x 16 x 24"
Height x Width x Length
Must fit in the overhead bin. This is your larger carry-on item, such as a rolling suitcase or duffel bag.
10 inches: Height (depth of bag)
16 inches: Width (across the bag)
24 inches: Length (tallest dimension)
Personal Item
8.5 x 13.5 x 18.5"
Height x Width x Length
Must fit under the seat in front of you. Examples include purses, backpacks, laptop bags, or briefcases.
8.5 inches: Height (depth of item)
13.5 inches: Width (across the item)
18.5 inches: Length (longest dimension)
How Southwest Measures Carry-On Bags
Southwest uses bag sizer devices at the gate and throughout the airport. Here's what you need to know about the measurement process:
Bag Sizing Process
- 1
Gate agents may ask to test your bag
If your bag looks oversized, agents will request you place it in the sizing bin
- 2
Includes wheels and handles
External handles, wheels, and pockets count toward total dimensions
- 3
Bags that don't fit must be gate-checked
Oversized bags are checked for free at the gate, but you won't have them during the flight
What Counts as a Personal Item?
Acceptable Personal Items
- • Standard backpack (school/day pack size)
- • Purse or handbag
- • Laptop bag or briefcase
- • Tote bag
- • Camera bag
- • Diaper bag
- • Small soft-sided cooler
- • Slim messenger bag
Too Large for Personal Item
- • Large hiking backpacks
- • Oversized tote bags
- • Gym bags over 18.5"
- • Rolling bags (counts as carry-on)
- • Large hard-sided cases
- • Oversized shopping bags
- • Bulky camera equipment bags
- • Full-size coolers
Popular Carry-On Bags That Fit
These dimensions and bag types consistently fit Southwest's carry-on requirements:
| Bag Type | Typical Dimensions | Fits? |
|---|---|---|
| 22" Rolling Carry-On | 9 x 14 x 22" | ✓ Yes |
| Standard Backpack | 7 x 12 x 17" | ✓ Yes (Personal) |
| Duffel Bag (Small) | 10 x 15 x 20" | ✓ Yes |
| Laptop Bag | 6 x 12 x 16" | ✓ Yes (Personal) |
| 24" Rolling Suitcase | 11 x 16 x 24" | ✗ Too Tall |
| Large Hiking Pack | 12 x 18 x 24" | ✗ Too Large |
Overhead Bin vs. Under Seat Storage
Overhead Bin
Your larger carry-on bag (up to 10x16x24") goes in the overhead bin. This space is limited, especially on full flights.
- • Southwest uses a first-come, first-served boarding policy
- • Early Bird Check-In helps secure overhead space
- • A-List status gives you earlier boarding
- • Last boarders may need to gate-check bags
Under Seat
Your personal item (up to 8.5x13.5x18.5") goes under the seat in front of you. This space is guaranteed for every passenger.
- • Always available regardless of boarding position
- • Easy access during flight
- • Less storage than overhead bin
- • Reduces legroom slightly
Special Carry-On Items
Certain items have special allowances and don't count toward your carry-on limit:
Items That Don't Count as Carry-On
Medical Devices
CPAP, oxygen, wheelchairs, canes, and assistive devices
Food for Infants
Baby formula, breast milk, and baby food in reasonable quantities
Jackets and Coats
Outerwear you're wearing or carrying doesn't count
Approved Assistive Devices
Strollers, car seats, and child restraint systems
Reading Material
Small books, magazines, or newspapers
Tips to Maximize Carry-On Space
Packing Tips
- • Use packing cubes to compress clothes
- • Roll clothes instead of folding
- • Wear bulky items on the plane
- • Use every pocket and compartment
- • Pack shoes first along the edges
Bag Selection
- • Choose soft-sided expandable bags
- • Bags with external compression straps
- • Multiple compartments for organization
- • Spinner wheels for easy maneuvering
- • Lightweight materials to maximize contents
Travel Hacks
- • Wear jacket with large pockets
- • Carry travel pillow with storage pocket
- • Use duty-free bags as extra storage
- • Combine purse inside backpack until boarded
- • Store items in coat pockets
What Happens If Your Bag Is Too Big?
Gate Check Process
If your carry-on doesn't fit in the sizing bin or overhead compartment, Southwest will gate-check it for free. Here's what happens:
- 1
Tag and Check
Agent tags your bag and it goes into the cargo hold at no charge
- 2
Board Without Bag
You won't have access to items in that bag during the flight
- 3
Retrieve at Destination
Pick up bag at baggage claim, not at the gate upon arrival
Frequently Asked Questions
Does Southwest charge for carry-on bags?
No, Southwest never charges for carry-on bags. All passengers get one carry-on bag (10x16x24") plus one personal item (8.5x13.5x18.5") completely free, regardless of fare type or status.
Can I bring two backpacks as my carry-on items?
Yes, if one backpack fits carry-on dimensions (10x16x24") and the other fits personal item dimensions (8.5x13.5x18.5"). However, the larger backpack must fit in the overhead bin and the smaller must fit under your seat.
Are purses included in the personal item limit?
Yes, a purse counts as your personal item. However, if you have a very small purse, you can often place it inside a larger personal item like a backpack until you board, then take it out for easier access during the flight.
What if the overhead bins are full when I board?
If you board late and overhead bins are full, Southwest will gate-check your carry-on bag for free. This is why many passengers purchase Early Bird Check-In or earn A-List status to board earlier and secure bin space.
Can I bring a carry-on and a guitar?
If your guitar is in a hard case that exceeds carry-on dimensions, it would need to be checked or you can purchase a seat for it. A guitar in a soft gig bag that fits 10x16x24" can be your carry-on if it fits in the overhead bin.
Do wheels and handles count toward carry-on size?
Yes, the total dimensions include wheels, handles, and any external pockets. When manufacturers list bag dimensions, verify whether they include these external features or just the main compartment.
Calculate Your Total Baggage Costs
While carry-on bags are always free, checked baggage fees can add up. Use our calculator to estimate your total costs based on your bags, status, and travel plans.
Calculate Checked Bag Fees →All information provided is for general informational purposes only and is based on publicly available data. Fee information was last verified against official Southwest baggage policy in March 2026. While we strive to keep the information accurate and up-to-date, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability, or availability of the information contained on this website.
Any reliance you place on such information is strictly at your own risk. In no event will the owner of this website be liable for any loss or damage including without limitation, indirect or consequential loss or damage, arising out of or in connection with the use of this website.