Flying with United Airlines? Knowing the carry-on size limits can help you avoid unexpected fees. Each passenger is allowed one carry-on (9” x 14” x 22”) and one personal item (9” x 10” x 17”). However, if you’re traveling in Basic Economy, you’re restricted to a personal item unless you qualify for an exception. Attempting to bring a full-size carry-on in Basic Economy results in a $25 gate handling fee plus checked bag charges. If you’re flying United Express, limited overhead space may require you to gate-check your bag.