What Happens If My Carry On is Too Big?

What will happen if your carry-on bag is too big depends on which airline you use.

Some airlines are strict and will make you pay to check the carry-on in if it’s just one inch too big, while other airlines will put your carry-on in a compartment in the cabin rather than in the overhead lockers. 

It’s always important to look into carry-on luggage requirements before you fly and to make sure you have prepared yourself for any additional fees you may incur by attempting to fly with an oversized carry-on bag.

Although many airlines will simply store carry-on bags that won’t fit in the overhead lockers elsewhere, some may insist you put it with the checked bags.

What is the Standard Measurement for a Carry-On Bag?

Many airlines differ in the size they offer for carry-on bags, with budget airlines tending to be less generous with their allowance. However, for most flights, the measurements for carry-on bags are approximately 22” x 14” x 9”, which American Airlines, United Airlines, and Delta Airlines use as their carry-on bag size.  

Additionally, in some cases, there is a weight limit for carry-on luggage. 

But, most airlines don’t pay attention if your bag is just one inch too big because it will still fit in the overhead bins. 

However, if you want an exact measurement, it is essential to note that these dimensions are external. Thus, if you measure your carry-on size yourself, you should include all wheels, handles, zips, flaps, and other accessories. 

You should also remember that your carry-on bag will bulge when full, which can take you over the limit. For some flights, this issue won’t matter, but you need to be aware of it before you fly.

Many airlines provide a sizer box as well so you can check whether your carry-on luggage is within their size limits. Yet, it is worth noting that some of these are actually an inch or two bigger than the exact size the airline says baggage should be, perhaps to allow for this bulge.

Finally, ignore bags in stores that claim they are of carry-on size because there is no such thing as a standard size for carry-ons. Always measure instead. 

What Happens if My Bag is too Big for an Overhead Locker?

If you get onto a plane and discover your carry-on luggage is too big for the overhead bin (maybe the wheels stick out), you should speak to a flight attendant. It is essential to do this, even if you are worried about getting charged for an oversized bag just one inch too big.

Often, attendants have a closet to store oversized luggage after boarding. However, you shouldn’t depend on this, because these areas have limited space and if yours won’t fit, you will probably have to put it in with check luggage.  

Also, if everyone carries bags too large for the lockers, these closets fill up quickly, and the last people to board end up having to get their bags gate checked. Therefore, it may be worth trying to be one of the first onto the plane if you know your bag is too large.

Further, don’t try to put oversized bags in the aisle or on a spare seat. The cabin crew will ask you to move them for the sake of other passengers. 

Luggage in the aisle is a safety hazard and will stop other travelers from moving around, so you have to keep bags properly stored throughout the flight. 

Should I Take a Carry-On That is too Big?

If you are struggling to make everything fit into your carry-on, there’s a lot of temptation to take a large one, even if you know it won’t fit the airline’s requirements. Whether you decide to do so or not depends on a few things, such as whether you can afford the extra fee to check the bag if required. 

For instance, if the plane does not have space for your carry-on in the cabin, you must gate-check it. Gate checking a bag can be expensive, particularly if you already have checked luggage in the hold. 

Thus, it may be best to bring a smaller bag to avoid paying for bags slightly larger than they should be. 

But, if you are happy to take this risk, there’s little penalty for trying to get away with a bigger bag, especially if it’s just one inch too big for the baggage allowance.

However, you should remember that if you have to check it, you will not have access to anything in the bag for the duration of the flight. You also won’t be able to access it if the flight attendants place it in a storage closet.

So, if your carry-on contains things you wanted or needed for the flight, you could leave yourself in a frustrating position. You may also end up having to carry essentials in your hands, which isn’t fun and puts you at risk of losing something important.

Do I Have to use the Sizer by the Gate?

No, you do not have to use the sizer unless an airline employee asks you to. Usually, employees will only ask if your bag looks particularly big or if the overhead lockers are getting too full.

If your bag is oversized, they may ask you to pay a gate checking fee, and some major airlines even add a secondary handling fee to discourage passengers from bringing oversized bags. Sometimes, they won’t charge you if it’s just one inch too big, yet it’s best if you prepare yourself.  

But, if you print your boarding pass out online, you can head right to the boarding gate, which makes it less likely someone will notice your cabin baggage is too big. Also, you should try not to draw attention to yourself so you can board without an issue. 

Will an Airline Ever Ask Me to Check a Carry-On That is not too Big?

If the cabin runs out of space, gate agents will make you gate-check bags that are the correct size. However, the airline should not charge you a checked bag fee because they have already agreed to let you carry a bag of that size for free.

Thus, make sure your carry-on has a tag to help you recognize it if it does end up at baggage claim, and remember to remove any valuables you don’t want in the hold. You should bring a small bag as a personal item just in case. 

And remember, personal items can be things such as a duffel bag, diaper bag, or small backpack. But, they must fit underneath the seat in front of you, so it may be hard to find a personal item bag with wheels. 


Often, nothing will happen if you take a carry-on that is too big, especially if it is only a little over the size limit and the agents don’t notice. Sometimes, the flying crew will store oversized luggage in a closet in the cabin, but other times you have to check it, so it doesn’t bother other passengers.