Photo by Mihaela Claudia Puscas on UnsplashSouthwest allows a carry-on of 24 inches long, 16 inches wide and 10 inches high — the biggest cabin bag box of the eight airlines on this page, by a wide margin. A bag that is legal on Southwest is roughly 39% more volume than one built to the usual American 22 x 14 x 9 limit. Southwest also publishes less than the others: no centimetres, no weight limit for the cabin, and no numbers at all for the personal item.
The numbers, exactly as Southwest Airlines prints them
| What Southwest Airlines publishes | Official figure |
|---|---|
| Carry-on (inches) | 24 × 16 × 10 in |
| Carry-on (centimetres) | 61 × 40.6 × 25.4 cm (converted) |
| Personal item (inches) | not published |
| Personal item (centimetres) | not published |
| Carry-on weight limit | not published |
| Wheels and handles counted? | Yes |
| Checked bag: max weight | 50 lb |
| Checked bag: max total size | 62 in |
Where these numbers come from: Southwest Airlines carry-on page, Southwest Airlines checked bag page. Read and recorded on 2026-08-31. Every figure on this page is copied from those pages — nothing here is estimated. Airlines change baggage rules without notice, so check the official page before you fly.
What the extra four inches are actually worth
Put Southwest's box next to the American standard and the gap is easy to underestimate. 24 x 16 x 10 inches is 3,840 cubic inches. 22 x 14 x 9 is 2,772. That is around a 39% increase, which in practice is the difference between three days of clothes and five, or between leaving the shoes at home and packing them.
What you cannot do is take the Southwest-sized bag anywhere else in this group. A 24 x 16 x 10 bag is over the limit on six of the seven other airlines here, in every direction. Frontier is the only one with the same box, and Frontier charges for the carry-on. If you own one bag and fly more than one airline, the Southwest allowance is not a size to buy for — it is a size to enjoy when you happen to be on Southwest.
Southwest's page is also notably sparse, and the gaps are as useful to know as the numbers. There is no published personal item dimension at all — only a placement rule ("goes under the seat in front of you") and a list of examples: purse, briefcase, laptop case, backpack, pillow, blanket, small camera. There is no cabin weight limit published, and no centimetre conversion anywhere. If you are flying Southwest on a connecting itinerary with a partner airline, Southwest notes their guidelines may differ — and the partner's smaller box is the one that governs.
The checked side changed the calculation for a lot of Southwest travellers. The page now states plainly that "checked baggage fees apply," alongside a standard limit of 62 inches and up to 50 pounds per bag. The generous cabin allowance is what is left of the old proposition, which is one reason it is worth using properly.
Measuring your own bag against these numbers
The bag most retailers label "the standard carry-on" is 22 x 14 x 9 inches. Converted exactly, that is 55.88 x 35.56 x 22.86 cm, and the three sides add to 114.3 cm. Held against Southwest Airlines's published limits, here is where it stands.
It fits. Every side of the standard bag is inside Southwest Airlines's published maximum of 61 × 40.6 × 25.4 cm. That gives you room to spare in the directions where it matters, but the margin exists only for an unpacked bag: soft sides bulge, and hard shells bow at the lid when overfilled.
The reverse question matters just as much if you already own luggage. A bag bought to fit Frontier Airlines, Air Canada, JetBlue, American Airlines, United Airlines, Delta Air Lines, Korean Air also clears Southwest Airlines.
Whichever airline you are flying, measure the same way the airline does: bag packed, tape across the widest bulge rather than the frame, wheels and handle included, expansion zip closed. Every airline on this page that says anything about wheels says they count.
What Southwest Airlines does not publish
These were checked against Southwest Airlines's own baggage pages on 2026-08-31. The following are simply not stated there, so treat any number you find elsewhere for them as somebody's inference rather than a rule:
- A carry-on weight limit
- A carry-on weight limit in pounds
- The carry-on size in centimetres
- A combined length + width + height cap
- Personal item dimensions in inches
- Personal item dimensions in centimetres
- A personal item weight limit
- The checked bag size in centimetres
- The checked bag weight in kilograms
- How many checked bags are included
The personal item gap is the one that costs people. Southwest describes where the item goes and gives examples, but publishes no dimensions at all. If you need a working number to shop against, plan to a stricter airline's published figure instead: American's 18 x 14 x 8 inches is a safe planning size, and United's 17 x 10 x 9 is the strictest of the eight.
How Southwest Airlines compares with the other seven
Southwest and Frontier share the largest cabin box in this group. Every other airline here is smaller in all three directions. Southwest Airlines has the largest published cabin box of the eight, at 62.9 litres. Volume is the published box multiplied out, which is the fairest way to compare boxes of different shapes.
| Airline | Carry-on (in) | Carry-on (cm) | Volume (L) | Weight cap | Personal item (in) |
|---|---|---|---|---|---|
| Southwest Airlines | 24 × 16 × 10 in | 61 × 40.6 × 25.4 cm† | 62.9 | — | not published |
| Frontier Airlines | 24 × 16 × 10 in | 61 × 40.6 × 25.4 cm† | 62.9 | 35 lb | 18 × 14 × 8 in |
† converted from the figure the airline does publish. Southwest and Frontier publish inches only; Korean Air publishes centimetres only. Everything without a dagger is printed on the airline's own page in that unit.
The full eight-airline table, including checked bag limits, is on the comparison page. Alaska Airlines is deliberately absent from it: its baggage pages would not open to us, and we would rather leave a gap than print a figure we could not read on an official page.
If you fly Southwest and anything else
Buy a 22 x 14 x 9 bag as your everyday case and treat Southwest's 24 x 16 x 10 as headroom rather than a target — unless you fly Southwest almost exclusively, in which case the larger box is free capacity you are otherwise throwing away.
Because Southwest publishes no personal item dimensions, use another airline's number as your working limit if you are travelling on a mixed itinerary. American's 18 x 14 x 8 is a safe planning figure; United's 17 x 10 x 9 is the strictest here and the safest of all.
The other seven airlines
- Frontier Airlines carry-on and checked bag sizes
- Air Canada carry-on and checked bag sizes
- JetBlue carry-on and checked bag sizes
- American Airlines carry-on and checked bag sizes
- United Airlines carry-on and checked bag sizes
- Delta Air Lines carry-on and checked bag sizes
- Korean Air carry-on and checked bag sizes
Related pages on TripPack
- All eight airlines in one table — carry-on, personal item and checked limits side by side.
- Carry-on packing list — what to actually put in the bag once you know it fits.
- How to measure a carry-on bag — where to hold the tape.
- Baggage weight limits explained.