United is the only one of the big four that takes your carry-on away on Basic Economy. That is the single most expensive detail in United baggage rules, and it is easy to miss when comparing fares.
On most routes a Basic Economy ticket buys you a personal item and nothing else. Your roller has to be checked.
The Basic Economy carry-on rule
Delta and American both let Basic Economy passengers bring a full size carry-on. United does not.
Turn up at the gate with one and you pay to check it, at airport prices. That can erase the fare saving in a single transaction.
Compare the total honestly. A United Basic Economy fare plus a checked bag is often dearer than a Delta Main Cabin fare that includes the carry-on.
What United baggage rules allow in the cabin
The carry-on limit is 22 x 14 x 9 inches, or 56 x 35 x 23 cm. That includes the handle and wheels.
The personal item is 17 x 10 x 9 inches, or 43 x 25 x 22 cm. That is the tightest personal item among the big US carriers.
It matters more than it sounds. American allows 18 x 14 x 8, which is four inches wider.
A backpack that passes as a personal item on American can fail on United. If you fly both, pack to United’s limit.
One small mercy: a handbag does not count as a third item. It has to go inside your carry-on or personal item.
Checked bags
Checked bags run to 30 x 20 x 12 inches and 50 pounds in economy.
United does not publish one flat checked bag fee. Pricing runs through a per itinerary calculator instead, so the number depends on your route and fare.
Check the fee at booking rather than assuming a standard figure. It is one of the less transparent parts of United baggage rules.
Powders and liquids
United repeats the security limits on its own baggage pages, which is useful. Liquids follow the 3.4 ounce rule in a quart bag.
Powders over 12 ounces can be brought domestically but may need separate screening. Our liquids packer works out what fits.
Smart bags need their lithium batteries removed before boarding. That applies across carriers, not just United.
The bottom line
United baggage rules are standard on size and strict on fare class. The 22 x 14 x 9 carry-on matches the industry, but Basic Economy cannot use it.
Watch the personal item too, since 17 x 10 x 9 is the smallest of the majors.
Compare before booking with our airline guides, check what bags cost, and confirm your bag with the size checker.