As of 2026, United Airlines generally does not weigh carry-on bags for most domestic and international flights, focusing instead on size dimensions (22×14×9 inches). However, there is a catch: if you are flying Basic Economy on a domestic route, you are only permitted one small personal item that fits under the seat (17×10×9 inches); a full-sized carry-on is not allowed. While weight isn't usually checked at the gate in the U.S., United's partners on international routes (like Lufthansa or ANA) may enforce a weight limit of 7–8 kg (15–17 lbs). If a bag appears visibly heavy or oversized, agents may require it to be weighed or gate-checked to ensure it doesn't exceed the structural limits of the overhead bins.