Personal Item vs Carry-On: Size Limits by Airline (2026)

You're at the gate. The agent is eyeing your bag. You're doing quick math on whether "slightly over" counts as over.

It does, and it usually costs more at the gate than anywhere else.

The confusing part is that every airline draws the line between a personal item and a carry-on in a different place. So we pulled the current limits for nine major US and European airlines into one table, straight from their own websites, and added the packing tricks that keep you on the right side of the sizer.

Personal item vs carry-on: what's the difference?

A personal item is the smaller bag that has to fit under the seat in front of you. Think a backpack, laptop bag, purse or tote.

A carry-on is the bigger bag that goes in the overhead bin. Usually a roller suitcase or a large travel backpack.

On most full-fare tickets, you get one of each for free. On basic economy and budget airlines, the personal item is often the only free bag, which is why its size suddenly matters a lot.

Personal item size and carry-on limits by airline (2026)

All sizes include handles and wheels. Inches are length x width x height.

Checked on each airline's official website in October 2026. Rules change, so always double-check your booking before you fly.

What the table doesn't tell you:

• United has the smallest US personal item. At 17 x 10 x 9 in, it's a full 4 inches narrower than American's. And on United Basic Economy, that personal item is all you get on most domestic routes.
• "No set size" doesn't mean "anything goes." Delta and Southwest only ask that your bag fits under the seat. On a full flight with a narrow seat, that's a stricter test than it sounds.
• Ryanair is the strictest of all. 40 x 30 x 20 cm is smaller than most everyday backpacks, so measure before you go.

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

It can be either. Shoulder straps don't make it a personal item. Size does.

A slim 20L daypack will pass as a personal item almost everywhere. A 35L travel backpack is a carry-on, full stop. Carry-on backpack size limits are the same as for any carry-on: usually 22 x 14 x 9 in in the US. The tricky zone is in between, where the same bag passes on American and fails on United.

Take our own GRID Backpack Pro as an example. It measures 45 x 29 x 17 cm (17.7 x 11.4 x 6.7 in) as a 26L daily bag and expands to 21 cm (8.3 in) deep at 31L. On paper, that means:

1. As a carry-on, it fits every airline in the table, at both sizes. On Ryanair, keep it unexpanded to stay under the 20 cm depth limit.

2. As a personal item, it fits American, Spirit, Frontier and easyJet when unexpanded. Expanded, it's 0.3 in too deep for the 8 in limit.

3. It's too big to be a personal item on United, JetBlue and Ryanair. On those airlines, fly it as your carry-on.

That's the whole idea of an expandable backpack: one bag that can play both roles depending on the airline and the trip.

MEET THE GRID BACKPACK PRO

How to measure your bag (the way the airline will)

Gate agents don't care what the label says. They care whether it slides into the sizer.

1. Pack it first. A bag that measures 8 in deep empty can easily hit 10 in once it's stuffed. Measure it the way you'll fly with it.

2. Include everything that sticks out. Wheels, handles, side pockets with a water bottle in them. All of it counts.

3. Measure the deepest point. For soft bags, that's usually the front pocket, not the main compartment.

4. Leave half an inch of margin. Tape measures are kinder than metal sizers.

How to fit more into a personal item

The goal isn't a bigger bag. It's less air in the bag you have.

1. Vacuum-pack your clothes. Clothes are mostly air. A Vacuum Kit Pro bag saves up to 70% of the space, and its pump is TSA-approved. Here's our guide to vacuum bags and TSA rules.

2. Wear the bulk. Jacket, boots and your thickest sweater go on your body, not in your bag. Most airlines don't count a jacket as a bag. United, for example, lists coats among the extras you can bring for free.

3. Hang it, don't stuff it. If you're staying a few nights, a Compression Closet compresses a week of clothes to 38 x 25 x 5 cm and hangs up as a closet when you land. More in the Compression Closet launch.

4. Pick a bag with structure. Soft bags bulge in all the wrong places. A structured backpack keeps its shape, so what fits at home still fits at the sizer.

5. Shrink your wallet and keys. A bulky bifold and a loose set of keys eat pocket space you'll want for your passport and phone. A slim Cardholder Pro holds up to 14 cards in a fraction of the room, and a key organizer turns a jangling key ring into one slim stack.

What to keep in your personal item, always

Even if you have a carry-on, it can get gate-checked when the overhead bins fill up. United even recommends keeping medication and essentials in your personal item for that exact reason.

So the personal item is your "if everything else disappears" bag:

• Passport, ID and wallet
• Medication
• Phone, charger and power bank (power banks can't go in checked bags)
• Laptop and other electronics
• Keys
• One change of clothes

If your carry-on gets gate-checked

Gate-checked bags are exactly the ones that end up on the wrong carousel. Slip a Tracker Card into your carry-on and you'll see where it is in Apple Find My or Google Find Hub, whichever phone you carry. No subscription needed.

More on that in our guide to the best luggage trackers for 2026.

TLDR

Personal items go under the seat, carry-ons go overhead. Most US airlines allow a 22 x 14 x 9 in carry-on, but personal item limits range from 17 x 10 x 9 in on United to 18 x 14 x 8 in on American, Spirit and Frontier. In Europe, Ryanair's 40 x 30 x 20 cm is the one to watch.

Pack less air, measure the bag packed, and pick one bag that can do both jobs.

Going carry-on only? See how we fit two weeks into a carry-on.

GET THE GRID BACKPACK PRO →

FAQs

What is the standard personal item size?
There's no single standard. 18 x 14 x 8 in is common in the US (American, Spirit and Frontier), but United allows only 17 x 10 x 9 in and JetBlue 17 x 13 x 8 in. Delta and Southwest have no set size, as long as it fits under the seat.

What is the difference between a personal item and a carry-on?
A personal item fits under the seat in front of you. A carry-on goes in the overhead bin and is usually larger, typically up to 22 x 14 x 9 in on US airlines.

Can a backpack be a personal item?
Yes, if it fits that airline's personal item limits. Most slim daypacks do. Larger travel backpacks usually count as a carry-on.

Is the GRID Backpack Pro a personal item or a carry-on?
It's a carry-on on every airline in our table. Unexpanded (45 x 29 x 17 cm), it also meets the personal item limits of American, Spirit, Frontier and easyJet, but not United, JetBlue or Ryanair.

Do airlines actually measure personal items?
They can, especially budget airlines like Spirit, Frontier and Ryanair, where paying for an oversized bag at the gate costs more than adding it when you book. Any airline can make you check a bag that doesn't fit.

Can I bring a personal item and a carry-on on basic economy?
It depends on the airline. United Basic Economy allows only a personal item on most routes, while other airlines include a carry-on on basic fares. Check your fare rules before you book.