Personal Item vs Carry-On: US Airline Size Rules (United, Delta, American, Southwest)

Short answer: on United, Delta and American, the standard overhead carry-on limit is 22 × 14 × 9 in (about 56 × 35 × 23 cm), including wheels and handles. Southwest allows 24 × 16 × 10 in. The free personal item that goes under the seat is much smaller: United lists 17 × 10 × 9 in and American 18 × 14 × 8 in, while Delta and Southwest don’t publish a size and just say it must fit under the seat in front of you.

Last checked: 3 October 2026, on each airline’s official baggage page (linked below). Rules vary by fare (Basic Economy in particular), route and aircraft, and they change. Always check your airline’s current rules for your booking before you fly.

US airline carry-on and personal item sizes (2026)

What counts as a personal item vs a carry-on?

• Personal item: a purse, laptop bag, small backpack or similar that fits under the seat in front of you. It’s the one bag that is (almost) always included, even on Basic Economy.
• Carry-on: the larger bag for the overhead bin. Included on most US mainline fares, but often not on Basic Economy (check your fare).
• Gate checks happen. On full flights, overhead space can run out. Keep medication, keys, passport, chargers and valuables in your personal item in case the bigger bag is gate-checked.

Measuring a backpack properly

1. Pack it the way you’ll actually travel. A stuffed backpack is thicker than its listed size.
2. Measure the longest point including the grab handle, side pockets and anything strapped on.
3. Check each dimension separately. On Delta, also check that the total (length + width + height) is 45 linear inches or less.
4. If you’re close, test it at home in a box or a frame taped to the floor.

Flying Europe and the US on one trip?

European budget carriers are stricter on the free bag (often 40 × 30 × 20 cm) and many charge for an overhead cabin bag. See our EU & UK airline cabin bag size table. On a mixed itinerary, plan around the strictest airline you’ll fly.

Where the Airbag Lite fits

We make the Airbag Lite vacuum compression carry-on backpack. Here is the honest comparison against the published US numbers:

• Packed size: 48 × 32 × 10 cm (approx. 19 × 12.5 × 4 in). That is within the 22 × 14 × 9 in carry-on limit published by United, Delta and American, and within Southwest’s 24 × 16 × 10 in.
• Don’t plan on it as a personal item. At about 19 in long it is longer than United’s 17 in and American’s 18 in personal-item limits. Delta and Southwest don’t publish a personal-item size.
• It expands for extra packing (to 48 × 32 × 15 cm). Don’t assume the expanded bag will be accepted in the cabin. Check your airline.
• The Air Pump Lite is included free (not sold separately). You press soft clothes down by hand, then the pump draws out the remaining air.

More size questions are answered in our FAQ, and the week-in-a-carry-on guide shows how to fill a 22 × 14 × 9 in bag efficiently.

FAQ

Is a backpack a personal item or a carry-on?

It depends on its size. United, American, Delta and Southwest all list backpacks as possible personal items, but only if they fit under the seat (and within the published personal-item size where there is one). Larger backpacks count as your carry-on.

Do wheels and handles count?

Yes. United, Delta, American and Southwest all include wheels and handles in the carry-on measurement.

Can I bring a carry-on on Basic Economy?

On United, Basic Economy usually includes only a personal item. Other airlines’ Basic fares differ and change, so check your fare rules when you book.

Sources checked 3 October 2026: United “Bags”, Delta “Carry-On Baggage”, American Airlines “Carry-on bags and size limits”, Southwest “Carryon and Personal Item Policy”. PackLite Gear is not affiliated with any airline listed.

Comparing with European airlines? Our 2026 airline cabin bag size chart puts 20 EU, UK and US airlines side by side, each with its official source.