How strict is United Airlines First class with carry-on luggage size?

I have a laptop bag which I measured using tape and it fits within dimensions they mentioned in their website for carry-on item. I am still worried since I am not exactly sure how will they make sure carry-on luggage is of the desired size?

I don't want to convert it into check-in luggage because besides laptop it contains important items like my passport. Can I use carry a folder as my personal item in the worst case scenario?

  • I sometimes carry my passport and boarding pass etc. in a normal orange folder which is easy to spot and my carry-on is almost always oversized and overweight but I've had no problems taking it with me on-board. Aug 23, 2021 at 0:59
  • Where do you keep your orange folder once inside the flight? do you just hold on to it?
    – noname
    Aug 23, 2021 at 1:06
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    The seat in front of you and sometimes the bulkhead usually has a pocket for magazines. While it is easy to slip a folder or passport into it, it seems to be much easier to forget something there!
    – Itai
    Aug 23, 2021 at 1:30
  • @noname I usually do it when I'm travelling with a check-in luggage + backpack and then I keep it in the backpack. I don't expect to carry it separately. Currently the backpack travels folded in my carry-on and the passport's in an easy-to-access pocket of the carry-on as I use my Schengen ID card most of the time which is in my wallet. Aug 23, 2021 at 13:46
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    In the U.S., on any airline, the only case I've seen them be strict on bag sizes is if the aircraft is a regional jet with restricted overhead bin space (e.g. Embraer 175). Even so, they will offer to check the bag free of charge as they figure it would've been accepted if it weren't for the aircraft type.
    – gparyani
    Aug 23, 2021 at 20:07

5 Answers 5


How strict is United Airlines First class with carry-on luggage size?

Not at all.

The published carry-on limit is 9"x14"x22" and the actual sizer1 dimensions are 10"x15"x23". For personal items, the published is 9"x10"x17" where the actual sizer dimensions are 9"x11"x18".

However an airline knows which side of the bread is buttered and unless you try to carry on something truly atrocious, no one is going to pester first class customers with the sizer. Air Canada at one time measured the weight of the carry on bags even at business check in, that lasted about three months before they realized that's not good for, ahem, business.

1A sizer is a physical frame, usually located at the gate, that you/they can slide the bag into to check its size in case of issues.

  • 4
    I have never—in hundreds of flight—seen any airline use the sizer for any bag owned by any customer. Every single time, they just take bags regardless of size until the overhead containers are filled, and then they gate-check everything else that would have used them, again regardless of size. Once I was allowed to find a place to stow a small-ish duffel bag after they had announced they were gate-checking everything. I imagine if someone brought something truly egregious, and then argued about it, they would use the sizer to prove the customer wrong, but I’ve never seen that happen.
    – KRyan
    Aug 23, 2021 at 13:50
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    @KRyan I have seen carry on luggage checked for size with flights out of Ft Lauderdale IIRC with Southwest. So it does happen.
    – Peter M
    Aug 23, 2021 at 15:38
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    @KRyan I've seen several times at DFW passengers being told that their carry-on is too large and they have to check it in. I think it was American Airlines to international destinations. It didn't happen every time I flew but when it did, they were really obnoxious about it. One case I remember particularly well was a guy's (large) laptop case that fit exactly in the container but its fabric handle was over (the top surface was in line with the sizer frame so the fabric handle was sitting above the line) and they told him it's oversized.
    – xxbbcc
    Aug 23, 2021 at 16:05
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    @xxbbcc about 10 years ago at DFW on a domestic AA flight I saw someone arguing with the boarding staff about a bag whose main compartment and outside zipper pockets were bulging by about 3-4 inches (I'm amazed he was able to zip it shut and that didn't subsequently burst) and clearly wouldn't come close to fitting into the sizer box. It was comical to the extent I was thinking "first time flier", only to have him board without the bag a few rows away and spent about 10 minutes ranting to the person next to him about how this airline always hassles him about that bag. 🤦‍♂️ Aug 23, 2021 at 20:41
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    @KRyan, I have seen the sizer used a few times, on MD-80s and & 737s. I used to fly on business a lot, but I think I've mostly seen it happen primarily on a flight with mostly leisure travelers, full plane, late afternoon... Aug 25, 2021 at 3:00

Given that it fits, you have nothing to be worried about. You are absolutely required to have your passport with you and highly recommended to have your valuables with you, plus medicines and other essentials, so it is normal to use a carry-on or personal item (or both) to have these. Most laptops even fit in personal item sizes which are more restrictive than carry-on.

United is not strict at all about carry-on sizes and I have seen countless clearly oversized bags being taken into various short to long flights with them. On small planes they offer to take larger ones as gate checked luggage to those who have among the largest items, most typically roller bags.

While they do not actively measure carry-on size, there is a sizer at most gate entrances. This is essentially a metal cage the maximum size of the carry-on they allow. If your bag is suspected of being too large, you can be asked to place it in the cage. If it fits, then you are good to go. If it is not, then they can ask to convert it to checked luggage, in which case you may be charged an extra fee. You will usually be instructed to take out any valuable items and essentials.

A personal item is a good way of ensuring you will have your most important items with you and United, as the majority but not all airlines, allow passengers to bring one in addition to your carry-on. You can use pretty much anything as a personal item, even a folder as you suggested but I have been plastic and cloth bags as well as unpackaged items. It's a good idea to carry an extra cloth bag inside your carry-on that you can use to carry essentials in tight planes where even an allowed carry-on does not fit in some overhead bins and you end up in a seat without space under the seat in front of you or no seat in front of you at all.

  • Yes, you need to have your passport on you because in an emergency they may divert to a country where you need to present it, e.g. the Ryanair divert to Belarus. Even a US domestic flight can divert to Canada unexpectedly. Aug 23, 2021 at 20:26
  • I'm trying to imagine a domestic US route that would divert to Canada - even if you were flying from SEA to somewhere in Alaska, there aren't that many Canadian runways in between. I guess BOS to Minneapolis might divert to Toronto. Even then, I don't think that there'd be an expectation that any of the passengers would have a passport (or a visa, for those who'd need one). They'd just leave everyone on the plane until the ground stop at the destination ended.
    – Flydog57
    Aug 23, 2021 at 21:03
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    @Flydog57: Great Circle paths bend pretty far North when you're North of the equator - for example, the most direct path between Boston and Seattle goes pretty far into Canada...
    – poncho
    Aug 24, 2021 at 16:49
  • @Flydog57 BOS to ORD/MDW, DTW, MSP, SEA, PDX, SFO/OAK, LAS, SLC, DEN, and even LAX or HNL all overfly Canada. These flights would of course prefer to divert to BUF or DTW, but in an emergency could end up in Toronto or even the notorious "Fake London." MIA to SJU overflies the Bahamas and Turks and Caicos. IAH to HNL probably overflies Mexico.
    – A. R.
    Jun 20, 2023 at 17:57

There are two issues that need to be considered :

  1. Whether the staff will let you board with your bag, and
  2. Whether there is sufficient space for the bag once you do board.

The first of these you have basically answered yourself - if it is within the size allowed, then you will be fine. United Airlines do not consider the weight of carry-on bags, and you've already stated you are within the size guidelines.

To your specific question around how strict they are with sizes, the answer answer is "it depends". In general they are not overly strict - especially for passengers boarding in the earlier "boarding groups", which includes First Class passengers. On occasion a specific gate agent will decide to be more strict, including requiring all passengers with bags that look even close to the allowed size to check their bag against the "sizer" to make sure it is within the requirements - however this is rare.

The second issue is one of space on the plane. Even if your bag is within the size requirements, if the plane runs out of space for bags in the cabin then you may be forced to "gate check" the bag (ie, they will take the bag and treat it as checked luggag). Whilst it is common for this to occur (especially on a full or near full flight) you can avoid this occurring by boarding the plane earlier. By virtue of being in First Class, you will be in "Boarding Group 1" which means you will be allowed board relatively early - as long as you board at that time you will have no issue with space.

If you are forced to check the bag for any reason then you will be allowed remove anything you need from it and carry them onto the plane separately. Obviously that's still not ideal, but it means that you can remove your passport/laptop/etc from the bags and carry them with you.

  • One thing to worry about -- United has a lot of small planes, which tend to have smaller spaces for carry-on luggage. If you're on one, many larger bags that fit within their published size requirements will still not fit on the plane and must be gate-checked, regardless of when you board. Aug 23, 2021 at 17:16
  • It should say the aircraft type if you look up your flight details on United's website. If you're on a Boeing or Airbus aircraft (model number starts with B, 7, or A) you'll be fine. If you're on an Embraer or Bombardier (model number starts with E or CRJ), larger carry-on bags might not fit and will need to be gate-checked. Generally they only use those smaller planes for very short flights and/or flights to rather small airports. Aug 23, 2021 at 17:19

At most airports, carry-on size is gauged at the security process, which no single airline has any control over. I've read of cases where airlines have advertised more generous carry-on sizes, for their passengers to find themselves facing issues at security.

Once you're past that stage, the worse that's likely to happen is that as you board, you'll be told that overhead storage is limited and you'll need to "gate-check" the bag you were hoping to put overhead. I presume that this is less likely in the front-of-the-bus classes than where I normally sit.

I'm an infrequent traveler and hardly in the position of offering sage travel advice, but I'd keep my passport in a pocket, because losing it would be such a pain. I tend to make sure I have a shirt pocket I can load up for things I might want to handle while I'm strapped in (boarding pass to resolve set assignment questions; phone; a pen) since it can be difficult to get to even your under-seat storage during turbulence, or when your tray table is down, or just if the seat next to you is occupied.


I've got a fair amount of experience traveling internationally and am keenly aware of the restrictions imposed by different airlines. Unless one is on a economy fare that most U.S. airlines are now offering, you can bring a carry on bag that fits in the overhead compartment and a "personal item" the must fit under the seat. I have a small pack that holds my laptop, a tablet, head phones, and anything I might want immediate access to during a flight. I have a few medications that I need that go in there as well. I don't mind gate checking a carry-on but don't want to gate-check a bag with my laptop and other "essentials".

I also have a small travel wallet with a cord that goes around my neck. It holds my passport, boarding passes, a pen (for filling out customs forms), and some cash (both U.S. and, if I have some, the currency at my destination). I wear it around my neck until I board, then put it into my personal item, and remove it before de-planing. I've never had an issue carrying it with a carry-on bag and a personal item.

I have seen airlines check carry-on sizes, mostly when there is a full flight, but usually they ask for volunteers to gate check larger carry-ons either to be picked up just outside the plane, or someones checked through to a final destination (for free).

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