With more travelers skipping checked bags, knowing your airline’s carry-on rules can make all the difference. United’s carry-on size is 22 x 14 x 9 inches. Unless you’re flying Basic Economy, you can bring that plus a personal item.
Here’s a quick look at United’s carry-on policy, fees and tips to avoid gate-checking.
Carry-on details.
- Dimensions: 22 x 14 x 9 in (56 x 35.5 x 23 cm)
- Personal item size: 17 x 10 x 9 in (43 x 25.5 x 23 cm)
- Weight limit: No official limit, but you must lift your bag into the overhead bin.
- Allowance: Free carry-on + personal item on most fares; Basic Economy usually includes a personal item only
- Bags may be checked in a sizer at the gate, especially on full flights
- Overhead space: Not guaranteed – boarding earlier helps
United carry-on size and dimensions.
| Carry-on size limit | 22 x 14 x 9 in |
| Carry-on max weight | not specified |
Last updated and fact-checked: April 14, 2026.
United’s carry-on bag size is 22 x 14 x 9 inches (56 x 35.5 x 23 cm) and that measurement includes wheels, handles and attachments. Unless you have a Basic Economy ticket, you can bring one larger bag for the overhead bin and one smaller item for under the seat.
United does not specify a weight limit for carry-on luggage or personal items. The no-weight-limit policy is helpful, but you still need to lift your bag into the overhead bin yourself.
What is United’s personal item size?
United personal item size is 17 x 10 x 9 inches (43 x 25.5 x 23 cm), and it needs to fit under the seat in front of you. Think purses, laptop bags and small backpacks.
If you’re wondering whether your backpack qualifies as a personal item, the answer is straightforward: it needs to stay within those measurements and actually fit under the seat.
United also allows passengers to bring on extra items that do not count toward its allowance for personal items or carry-ons. And if you’re traveling with children, you’re also allowed extra children’s items such as a diaper bag or breast pump.
Does United allow a carry-on bag?
Yes – most United fares include a free carry-on bag and a personal item. If you’re flying Basic Economy, you’ll usually only get a personal item unless you qualify for an exception. Some Basic Economy tickets still include a carry-on.
This applies on flights to South America and on long-haul routes across the Atlantic and Pacific. You’ll also get a carry-on if you have MileagePlus Premier status, are traveling with a Premier member, hold a qualifying MileagePlus credit card, or have Star Alliance Gold status.
| Carry-on allowance | Basic Economy | Standard Economy |
|---|---|---|
| Carry-on bag | No full-size carry on* | 1 full-size carry-on |
| Personal item | 1 personal item | 1 personal item |
*Except on select international routes.
If you’re a light traveler and are headed to South America or across the Atlantic or Pacific, consider a Basic Economy ticket on United. Even in that lowest fare category, United allows passengers to bring a larger carry-on bag for free.
from expert traveler Blane Bachelor
Compare policies across airlines
How strict is United with carry-on size?
United has strict carry-on size limits – and they enforce them. Gate agents may ask you to place your bag in a sizer, especially on full flights or when overhead bin space is tight. The sizer matches the official 22 x 14 x 9 inch limit, so if your bag fits, you’re good. If not, it’ll need to be checked.
Carry-on size includes wheels, handles and external pockets. Soft-sided bags might pass if slightly overpacked, but anything that doesn’t fit the sizer can be flagged. Enforcement can vary by airport and how full the flight is, though United is testing automated bag scanning at some gates – a move that could make checks more consistent. Stick within the limit to avoid surprises.
What happens if your carry-on is too big?
If your carry-on exceeds United’s size limits, it will need to be checked at the gate. For standard fares, gate-checking is usually free if overhead bin space is full. However, if the bag is flagged as oversized before boarding, standard checked bag fees may apply.
For Basic Economy, where a full-size carry-on isn’t included, bringing an oversized bag to the gate means paying both the checked bag fee and an additional gate handling fee. To avoid charges, measure your bag before heading to the airport and make sure it meets United’s size requirements.
What are the TSA liquid limits for your United carry-on?
No matter your airline or fare class, TSA’s 3-1-1 rule applies to all carry-ons on US flights. Here’s how it breaks down:
- Each liquid must be 3.4 oz (100 ml) or less
- Pack them all into 1 quart-size clear bag
- 1 bag per traveler
Common items include shampoo, toothpaste, sunscreen and liquid makeup. Anything over 3.4 oz needs to go in a checked bag.
One common misconception: TSA PreCheck doesn’t skip the liquid rules. You’ll still need to follow 3-1-1, even with expedited screening.
What extra items can you bring on board United flights?
United allows passengers to bring on board extra items that do not count toward the carry-on allowance. The following items are neither considered a carry-on bag nor smaller personal item:
- Assistive/mobility devices such as walking canes
- Wearable articles of clothing, like coats or jackets
- Umbrellas
- Food or other items purchased at the airport
Can you bring strollers and car seats on United?
Like most major US carriers, United offers flexible carry-on options for travelers with children. Compact strollers are allowed onboard if they meet carry-on size guidelines when collapsed (United even calls out models like the GB Pockit). Strollers and car seats can also be checked for free at the airport or gate.
Some may qualify as carry-on items if they fit within size limits, and they don’t count toward your carry-on allowance.
In addition, a diaper bag, milk, and breast pump also may be brought onboard, even if you’re not traveling with your child, which is a thoughtful bonus for parents who are nursing. These items do not count toward the standard carry-on limit.
Children with their own seat on United.
As with all other carriers, children under two years old may travel as a lap infant for free. In this case, you will not be allowed to bring on a car seat for them. However, if you choose to purchase a seat for your child, they have the same carry-on allowances as adult passengers, as well as a car seat, if you choose to use one.
Car seat rules on United flights.
If you are using a car seat onboard, it must be FAA approved, and it must fit within the seat. Note that car seats are allowed only in window and middle seats, never the aisle or any seat in an exit row.
Car seats must be FAA-approved, however. And if you’re flying United Polaris business class on Boeing 767, 777, or 787 aircraft, car seats are not allowed in these cabins.
Traveling with a stroller on United.
United allows you to check one car seat and one stroller (or folding wagon) per child you’re traveling with for free. This can be done during check-in, at the ticket counter, or at the gate. However, large or non-collapsible strollers and non-folding wagons must be checked (at no charge) at the ticket counter, not at the gate. (Keep in mind that United does not specify a size for these).
If you prefer to gate check your stroller (or collapsable wagon) on United, be sure to get a tag from the gate agent prior to boarding. Amid the hassles of traveling with young children, this is an easy step to forget. But it’s an important one so you can board on time.
United carry-on rules for musical instruments.
You may bring a musical instrument onboard, but United specifies that it must be in a hard case. If the instrument fits within the carry-on luggage size for United, it can go in the overhead bin or, if it’s small enough, under the seat.
Keep in mind that, as with most carriers, United counts musical instruments as part of passengers’ carry-on allowance. So depending on your ticket category, your only other allowed carry-on bag will likely be a personal item that fits under the seat in front of you.
Another important heads-up for anyone traveling with musical instruments: They fall under United’s “Fragile Baggage” category. That means, the carrier does not assume responsibility for such items in case of loss or damage. Rules may differ for domestic and international travel
However, if you’re planning to bring a musical instrument onboard any flight, it’s a good idea to make sure you understand the rules – and perhaps consider purchasing insurance beforehand.
Expert tips to avoid gate-checking on United.
1. Know your boarding group.
Which boarding group you’re assigned will have a big impact on whether there will be enough room in the overhead bins for your carry-on bag. United Airlines has seven boarding groups, and generally speaking, space begins to fill up around Groups 4 and 5. Plan accordingly to avoid being forced to gate check your bag unexpectedly.
2. Consider Priority Boarding.
If you want to be assured that you will have room for your carry-on bag, consider purchasing Priority Boarding, which is available on certain flights worldwide. It’s slightly less than the cost of checking a bag and lets you avoid the stress of the overhead bin battle. Priority Boarding allows you to board with Group 2.
3. Watch out on United Express flights.
United’s network is supported by United Express flights, which are operated by regional carriers including Mesa Air, CommuteAir, and SkyWest Airlines. Aircraft on these carriers are smaller, and while they do allow carry-on bags, space is limited. (CommuteAir passengers are only allowed one personal item on board.) As a result, you’re more likely to have your bag gate checked on United Express flights.
4. Board as early as possible.
Even a bag that meets United’s carry-on size requirements can end up being gate-checked if overhead bin space runs out before you board. Boarding earlier is the most reliable way to secure space for your bag.
United Airlines carry-on bag FAQs.
For quick answers to your questions about United carry-on bag size or other concerns, see the intel below.
Generally, United does not weigh carry-on bags.The airline focuses on size restrictions and whether you can lift your bag into the overhead bin or fit it under the seat in front of you.
Yes, but they must fit within United’s carry-on allowance andsize dimensions. If your backpack qualifies as a personal item and your purse fits inside it or counts as your carry-on, you’re set.
For Economy and above, carry-on bags are free. Basic Economy domestic flights do not include a full-size carry-on. If you bring one and it’s gate-checked, you’ll pay the standard checked bag fee plus a gate handling surcharge. International Basic Economy on certain routes does include a free carry-on.
Yes. A backpack can be your carry-on bag if it fits within 22 x 14 x 9 inches, or your personal item if it fits within 17 x 10 x 9 inches. It needs to fit in the overhead bin or under the seat, respectively.
Yes – standard United Economy includes a carry-on bag and a personal item. The only exception is Basic Economy. On most Basic Economy tickets, you’re limited to just a personal item unless you qualify for an exception (like certain international routes or elite status).
Still have questions?
Luggage policies can be confusing. For an easy way to compare carry-on rules across airlines, check out our carry-on luggage guide. Need help deciding between a carry-on or checked bag? Or perhaps you’re stuck on what to pack? We have plenty of handy tips for that, too. Finally, don’t forget to check what’s allowed in a carry-on before you head to the airport.
