I have a very specific memory burned into my brain. I was at the United gate in Chicago with a bag I swore would fit. The agent looked at it, then at me, then at that little metal sizer like it was a courtroom. I did the gentle push. Then the not-so gentle push. The bag went in… kind of. The wheels stuck out like tiny rebels. I smiled anyway. The agent smiled back and slapped a tag on it. Good times.
If you want to keep your bag with you, avoid surprise fees, and just have a chill boarding experience, this guide will save you from that exact moment. Here is the simple version of United’s carry on rules in 2025, along with the stuff I learned the clumsy way.
What you can bring for free
On United, every passenger gets:
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One carry on bag that goes in the overhead bin
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One personal item that goes under the seat in front of you
That applies to regular economy and above. Basic Economy is a different story, and we will talk about it in a second. For now, just lock this in: overhead bag plus personal item is the standard on United.
The official sizes you need to know
United’s limits are the usual ones you see on big US airlines. The key is that the measurements include wheels and handles. Do not measure just the shell and then act surprised. I have done that. It ends badly.
Carry on size limit
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22 x 14 x 9 inches
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That is 56 x 35 x 23 cm if you are measuring in centimeters
Personal item size limit
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17 x 10 x 9 inches
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That is 43 x 25 x 22 cm
If your bag is right on the edge, a soft shell is your friend. It squishes a little. Hard shells do not negotiate.
What about weight limits
For domestic United flights, there is no official weight limit for your carry on. That does not mean you can show up with a gym-killer. If you can’t lift it into the bin by yourself, the crew can stop you from bringing it on board. Also, your shoulders will hate you.
If you are connecting to or from an international flight, especially with partners in Europe or Asia, you might see weight limits around 7 to 10 kg for the cabin bag. If that is your route, do a quick scale check at home. My personal comfort zone is under 25 lbs. I can still swing it into the bin without making a scene.
What counts as a personal item
United is pretty clear here. A backpack, purse, laptop bag, or small camera bag will do the trick as long as it slides under the seat. I prefer an under seat backpack with some structure but soft sides. It looks small but swallows a scary amount of stuff if you pack smart.
Things I have personally fit into an under seat bag without anyone blinking:
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Laptop with charger and mouse
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Big headphones
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A hoodie and a scarf
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Snacks for the flight and snacks for after the flight
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A small pair of foldable shoes because I like my feet happy
If in doubt, remember the magic words: soft and flexible. That under the seat space is weirdly shaped. Your bag should be able to wiggle.
Free extras that do not count toward your two-bag limit
Handy little freebies you can still carry:
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A coat or jacket
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An umbrella
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A duty free shopping bag
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A small bag of food
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Medical devices like a CPAP
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A diaper bag if you are traveling with an infant
These usually slide by with no drama at all.
The Basic Economy twist
Here is where United is stricter than some folks expect. On most Basic Economy itineraries, you are limited to one personal item that fits under the seat. No full size overhead bag. There are some international exceptions where a larger cabin bag is allowed, but for many domestic trips the rule is personal item only.
So what does that mean in real life?
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If you booked Basic Economy for a quick domestic hop, plan on one under seat bag only.
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If you show up with a big roller and you are not on one of the exception routes, you may be told to check it and pay the fee at the gate.
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You can still bring a coat, an umbrella, and other small extras, but do not expect overhead real estate.
If you love traveling light or you are just saving money, a Basic Economy personal-item-only approach can actually be kind of fun. You learn what you actually use. You also become emotionally attached to packing cubes. Ask me how I know.
How to avoid the dreaded gate check
Even if your bag is within the limits, it can still get sent to the hold if the bins fill up. That usually happens when you board late and folks before you played overhead Tetris with winter coats and giant backpacks.
Stuff that helps you keep your bag with you:
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Board as early as you can. United status, co-branded cards, or just being ready at the gate when your group is called all help.
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Use a bag that does not scream for attention. A sleek twenty one to twenty two inch case is less likely to get side-eyed than a chunky overstuffed roller.
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Keep valuables in the personal item. If a surprise gate check happens, you are not begging anyone to wait while you fish out your medication and your laptop.
Story time. On a Newark flight last year, my row boarded right as the last good bin went poof. I did that fast walk that is not really running and slipped my carry on into the closet size gap above 12C. The person in 12C gave me a look like I had taken their parking spot. I smiled, said thank you, and offered a snack later. It worked.
Small planes, small bins, small headache
United Express and other regional jets bring a different challenge. The overhead bins are tiny. You can have the most perfect twenty two by fourteen by nine carry on in the world and it still might not fit. In that case, you will do a valet check at the door and pick the bag up right on the jet bridge after landing. It is not terrible. Just keep your essentials in your personal item and you are fine.
Packing tips that just work
I am not trying to reinvent anything here. I am just telling you what has made my trips easier and my bags lighter.
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Roll your clothes instead of folding. Fewer wrinkles and better use of space.
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Use packing cubes. Put tops in one, bottoms in another, underwear in a small one. You will never go back.
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Wear your bulkiest items to the airport. Boots and a jacket on your body equals more room in the bag.
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Stuff little things inside your shoes. Socks, charging bricks, cables, even a tiny bottle of lotion with a cap that actually closes.
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Bring a compact laundry kit. A tiny bottle of detergent and a sink stopper lets you repeat outfits without smelling like an airport.
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Carry a folding tote. If you come home with extra stuff, use it as your personal item on the return flight.
Common mistakes to skip this year
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Measuring the case but not the wheels or handle. The wheels count. Sorry.
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Using a hard shell and then overstuffing it until it bulges. Hard shells do not forgive.
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Banking on empty bins if you are in a later group. Not a real plan.
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Assuming your Basic Economy ticket includes an overhead bag. On many routes it does not.
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Ignoring regional jets. Those bins are small. Plan on valet check.
Seasonal packing notes
Winter trips
Wear the coat. Pack a packable down layer. Use a compression bag for sweaters but do not go wild or you will end up with a dense little brick that hogs half your case.
Summer trips
Light fabrics, quick drying stuff, comfy sandals. A tiny travel fan makes you everyone’s best friend at the gate when the air is warm and slow.
Holiday travel
If you bring gifts, keep them unwrapped so security does not undo your hard work. A hard case helps keep fragile things safe.
Sample carry on packing lists you can steal
Two night business trip
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One pair of pants, two shirts, one light sweater
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Underwear and socks for each day plus one extra
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Toiletry kit in TSA friendly bottles
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Laptop and charger, phone charger, earbuds
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Slip on shoes for security and the plane
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Small umbrella and a packable tote
Seven to ten day casual trip
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Two pairs of pants or one pant one light skirt
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Three to four tops that mix and match
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One dress or one nicer shirt for a dinner
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Light jacket or cardigan
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Underwear and socks for four days and do a quick wash mid trip
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Sneakers you love to walk in and one sandal or flat
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Toiletry kit, meds, sunscreen stick, a tiny first aid packet
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Laundry kit and a folding tote for the way back
If you are Basic Economy with only a personal item, cut that list in half, swap pants for one pair of amazing jeans, and plan on a fast sink wash. It is honestly not that bad once you try it.
My favorite bags for United flights
I have tested more than I should admit. These are the ones that play nice with United’s limits and feel good to travel with.
Carry-On Roller Bags
1. Travelpro Platinum Elite 21” Expandable Spinner
If you’re flying United and want something that feels like it was made for the overhead bin, this is it. The Travelpro Platinum Elite 21” is lightweight, expandable, and has those smooth-as-butter spinner wheels that make airport sprints feel like a walk in the park. Plus, it’s within United’s carry-on size limits — even with the handle and wheels.
2. Samsonite Winfield 3 DLX Hardside Luggage 20”
This one’s for folks who love that clean, hard-shell look. The Samsonite Winfield 3 DLX is tough, stylish, and scuff-resistant, so it still looks new after a few rough baggage handlers. Fits perfectly in United’s sizers, no gate-check stress here.
Under-Seat Bags
1. Samsonite Underseat Carry-On Spinner
If you want to skip the overhead bin entirely, this is your move. Fits right under United’s seat and still holds a laptop, a change of clothes, and all your in-flight snacks.
2. Targus Compact Rolling Backpack
This one’s sneaky — it looks like a backpack, but it’s actually a rolling bag. Perfect if you’re carrying electronics and don’t want the weight on your shoulders.
Packing Cubes
1. Bagail 6 Set Packing Cubes
These are the MVPs for keeping your clothes from turning into a wrinkled mess. They’re soft enough to squish into any bag and cheap enough to grab a couple sets.
2. Eagle Creek Pack-It Original Cube Set
If you want packing cubes that will basically last forever, this is it. Lifetime warranty, durable fabric, and just the right sizes for carry-on travel.
3. Veken Packing Cubes
Best bang for your buck — comes with multiple sizes, a shoe bag, and laundry pouch. Ideal if you like everything super organized.
Quick answers to real questions
Do they actually measure bags at the gate
Sometimes. If the flight is full or your bag looks chunky, they might ask you to try the sizer.
Can I bring food
Yes for solid snacks. Liquids fall under the usual security rules, so keep those under the limit.
Can I bring a garment bag
Yes as long as it stays within the carry on size limit. Slim tri fold styles do best in the bins.
Can I bring a backpack and a purse
You can, but one of them counts as your personal item and needs to fit under the seat. I usually slip the purse inside the backpack and call it a day.
Does United charge for carry on bags
Not for regular economy and above. On many Basic Economy routes, a full size overhead bag is not allowed and may need to be checked for a fee.
What happens if my case is twenty three inches tall
If it still looks small and the wheels are tiny, you might slide through. If it obviously sticks out of the sizer, expect to check it. I would not risk it on a packed flight.
What about musical instruments
Small ones that fit in the bin or under the seat are fine. Bigger ones sometimes need a seat of their own. If it is precious, call ahead.
Final thoughts
United’s rules are not scary once you know the real edges. Measure your bag with the wheels and handle included. Use a personal item that can bend and wiggle into the space under the seat. Board as early as you can. Keep your valuables close. If you are on a small regional jet, be ready for a quick valet check and move on with your life.
Most of all, pack for the way you actually travel. A few solid outfits, the stuff you reach for every time, and a bag you can lift with one hand. Do that, and you will walk past the sizer like it is not even there. Which is the dream, right