Most big US airlines take a carry-on up to 22 x 14 x 9 inches, wheels and handles included. Southwest and Frontier allow a bit more at 24 x 16 x 10. Where travelers get caught is the personal item, and whether their fare includes a carry-on at all.
28 October 2026 · 7 min read
Here's every major US airline side by side. The last column is the one that costs people money at the gate.
| Airline | Carry-on | Personal item | Carry-on on the cheapest fare? |
|---|---|---|---|
| American | 22 x 14 x 9 in | 18 x 14 x 8 in | Yes, even Basic Economy |
| Delta | 22 x 14 x 9 in (45 in total) | No set size; must fit under the seat | Yes |
| United | 22 x 14 x 9 in | 17 x 10 x 9 in | No on Basic Economy, apart from some long-haul international routes |
| Southwest | 24 x 16 x 10 in | No set size; must fit under the seat | Yes |
| JetBlue | 22 x 14 x 9 in | 17 x 13 x 8 in | Yes, even Blue Basic |
| Alaska | 22 x 14 x 9 in | No set size; must fit under the seat | Yes |
| Frontier | 24 x 16 x 10 in, up to 35 lb | 18 x 14 x 8 in, up to 35 lb | No, a carry-on costs extra unless your bundle includes one |
| Allegiant | 22 x 14 x 9 in | 16 x 15 x 7 in | No, $15 to $70 each way when booked, $75 at the airport |
Sizes include wheels, handles and straps. Checked October 28, 2026. Airlines change these rules, so check your booking before you pack.
American takes a carry-on up to 22 x 14 x 9 inches (56 x 36 x 23 cm) and a personal item up to 18 x 14 x 8 inches, which has to fit under the seat in front of you. Both come free on every fare, Basic Economy included.
There's no official weight limit, but you need to be able to lift the bag into the overhead bin yourself. On a Basic Economy ticket you board late, so the bins may be full by the time you reach your row. If they are, the carry-on gets checked at the gate.
Delta's limit is 22 x 14 x 9 inches (56 x 35 x 23 cm), wheels and handles included. You also get one free personal item, such as a purse, laptop bag or small backpack, on every cabin class.
There's no carry-on weight limit on most Delta routes. The exceptions are a few airports in Asia, including Singapore, Beijing and Shanghai, where the bag may be weighed.
One Delta rule surprises people on short trips. On Delta Connection flights with 50 seats or fewer, only personal items go on board. Your carry-on gets a pink tag at the gate, travels in the hold for free, and comes back to you at the aircraft door.
United's carry-on limit is 22 x 14 x 9 inches, the same as American and Delta. The personal item is where United is stricter: 17 x 10 x 9 inches. A backpack that's fine as a personal item on American can be too wide for United.
The bigger catch is Basic Economy. On most United Basic Economy tickets you get a personal item only, with no full-size carry-on. The exceptions are some long-haul international routes and travelers with MileagePlus Premier status, a qualifying MileagePlus credit card or Star Alliance Gold status. If you need the overhead bin, compare the Basic Economy fare with standard Economy before you book.
Frontier's personal item can be up to 18 x 14 x 8 inches and 35 pounds, including handles, wheels and straps. It comes free with every fare.
A carry-on is a different story. Frontier charges for one on every fare unless it's part of a bundle or you have elite status. The size limit is 24 x 16 x 10 inches and 35 pounds. The price changes with your travel dates and when you buy, so add it when you book. Frontier says an item larger than the allowed size at the gate is subject to an additional charge.
Southwest has the roomiest carry-on limit on this list at 24 x 16 x 10 inches. It doesn't publish a personal item size, only that it must fit under the seat in front of you. Both are free on every fare.
JetBlue allows a 22 x 14 x 9 inch carry-on and a 17 x 13 x 8 inch personal item on every fare, Blue Basic included. Blue Basic boards last, so if the bins are full your bag is checked at the gate for free.
Alaska takes a 22 x 14 x 9 inch carry-on and a personal item that fits under the seat, free on every fare.
Allegiant includes one free personal item up to 16 x 15 x 7 inches. A 22 x 14 x 9 inch carry-on costs extra on every fare. It's cheapest when you add it at booking, between $15 and $70 each way depending on the route, and $75 each way if you pay at the airport.
If you fly several airlines, buy to the smallest limit and stop worrying about it.
Some things are banned from checked bags, so they have to ride with you.
Liquids in your carry-on still have to be in containers of 3.4 ounces (100 ml) or less, packed together in one quart-size bag.
US airlines mostly care about size, not weight. Many international airlines care about both. Singapore Airlines, for example, allows one cabin bag of up to 7 kg (about 15 pounds) in Economy and Premium Economy, with the three sides adding up to no more than 115 cm. The personal item can be up to 40 x 30 x 10 cm. Business and First Class get two cabin bags of 7 kg each.
If your trip connects onto a foreign airline, pack to the stricter rule of the two.
