Southwest Airlines Carry-On Baggage Allowance: Everything That's Free
Southwest still offers the most generous carry-on allowance of any major US airline — 1 free carry-on bag and 1 free personal item for every passenger, on every fare. Here's what qualifies, what the size limits are, and how to make the most of it.
Southwest Carry-On Allowance at a Glance
| Item | Quantity | Size Limit | Weight Limit | Fee |
|---|---|---|---|---|
| Carry-on bag | 1 | 10" × 16" × 24" | None | Free |
| Personal item | 1 | Fits under seat | None | Free |
| Checked bag (1st) | — | 62 linear inches | 50 lbs | $35 |
Carry-On Size Requirements
Southwest's carry-on size limit is 10" × 16" × 24" (height × width × depth). The bag must fit in the overhead bin. Most standard carry-on suitcases (20"–22" spinners) fall within this limit.
Size Reference
✓ Typically fits
- 20" carry-on spinner
- 21" carry-on suitcase
- Soft-sided carry-on bags
- Standard laptop backpacks
✗ May not fit / must check
- 24" suitcases (too large)
- Full-size garment bags
- Oversize hard cases
- Bags exceeding any dimension
What Counts as a Personal Item?
Southwest's policy for personal items is simple: it must fit under the seat in front of you. There is no published maximum size — the practical test is whether it fits.
Purse or handbag
Any size that fits under the seat qualifies
Laptop bag
Most laptop bags and sleeves fit easily
Small backpack
Day packs and school bags typically fit
Tote bag
Soft-sided totes compress to fit under the seat
Camera bag
Camera bags and cases that fit under the seat
Diaper bag
Counts as personal item (not an exemption)
How Southwest Compares to Other Airlines
| Airline | Carry-on fee | Personal item fee | Weight limit |
|---|---|---|---|
| Southwest | Free | Free | None |
| Delta | Free (most fares) | Free | None stated |
| United | $35 (Basic Economy) | Free | None stated |
| American | $35 (Basic Economy) | Free | None stated |
| Spirit | $39–$79+ | $6.99+ | 40 lbs |
Tips to Maximize Your Free Allowance
Pack heavy items in carry-on
No weight limit on carry-ons — put books, shoes, and dense items in the overhead bag to keep your checked bag under 50 lbs
Use a personal item as a second carry-on
A large tote or soft-sided bag that fits under the seat can hold as much as a small backpack — use all the space you're entitled to
Measure before you go
Bags right at 24" are risky — if your bag has exterior pockets, those count toward the dimension. Soft-sided bags compress more easily
Board early for overhead space
Southwest uses open seating. A-List status and Choice Extra fare passengers board first — earlier boarding means guaranteed overhead bin space near your seat
Gate-check if the bin is full
If overhead bins are full, gate agents will check your carry-on for free. You get it back at baggage claim (or sometimes at the gate)
Avoid oversize bags that must be checked
A bag that doesn't fit overhead will be gate-checked and treated as a standard checked bag — meaning $35 at the gate
Frequently Asked Questions
Can I bring a backpack and a carry-on on Southwest?
Yes. Southwest allows 1 carry-on bag and 1 personal item. A backpack that fits under the seat counts as your personal item. A larger bag that goes in the overhead bin counts as your carry-on. Both are free.
What happens if my carry-on doesn't fit in the overhead bin?
If your carry-on doesn't fit in the overhead bin, a gate agent will check it. This counts as a checked bag and you'll pay the standard checked bag fee ($35 for the first bag). To avoid this, make sure your bag is within the 10" × 16" × 24" limit.
Does Southwest charge for carry-on bags in Basic Economy?
Southwest doesn't have a Basic Economy fare like Delta or United. All Southwest fares (Basic, Choice, Choice Preferred, Choice Extra) include 1 free carry-on and 1 free personal item. Only checked bags incur fees.
Can I bring a full-size backpack as a personal item?
It depends on the size. A large hiking pack or full-size backpack likely won't fit under the seat. A school backpack, laptop backpack, or day pack typically does. If it fits under the seat in front of you, it qualifies as a personal item. If it doesn't fit under the seat, it must go in the overhead bin and counts as your carry-on.
Is a guitar or musical instrument allowed as a carry-on?
Small instruments that fit in the overhead bin (such as a guitar in a standard case) can be brought as carry-on baggage on a space-available basis. Southwest may require you to purchase an extra seat if the instrument is too large. Instruments too large for the overhead bin must be checked.
How many carry-on bags does Southwest allow?
Southwest allows 1 carry-on bag and 1 personal item per passenger, both free of charge. The carry-on must fit in the overhead bin (max 10" × 16" × 24"). The personal item must fit under the seat in front of you.
What is the size limit for a Southwest carry-on bag?
Southwest carry-on bags must not exceed 10" × 16" × 24" (height × width × depth). This is a combined linear dimension of 50 inches. There is no stated weight limit for carry-on bags.
What counts as a personal item on Southwest?
A personal item is any small bag that fits under the seat in front of you. This includes purses, laptop bags, backpacks, and small totes. Southwest does not publish a maximum size for personal items — the practical limit is what fits under the seat.
Is there a weight limit for Southwest carry-on bags?
Southwest does not enforce a weight limit for carry-on bags. The only requirement is that the bag fits in the overhead bin (within the 10" × 16" × 24" size limit).
Need to Check a Bag?
Calculate your exact checked bag fees — including overweight and oversize surcharges.
Open Baggage Fee Calculator →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.
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