Carry-on bag. The maximum dimensions for a carry-on bag are 9 inches x 14 inches x 22 inches (22 cm x 35 cm x 56 cm), including handles and wheels. The maximum dimensions for your personal item, such as a shoulder bag, backpack, laptop bag or other small item, are 9 inches x 10 inches x 17 inches (22 cm x 25 cm x 43 cm). To determine if a bag will fit onboard, bag sizers will be available in the airport lobby.