Carryon baggage avoids the need to wait for checked baggage in the baggage hall.
Air travel is the quickest way of getting from A to B, and it certainly feels a lot faster when you do not have to wait for checked baggage at the end of a flight. If you just have carryon, you can walk through arrivals and exit the airport, leaving the carousel queues behind. However, the size of carryon bag you are allowed to take into the cabin varies from airline to airline.
American and Continental
These two legacy carriers allow one carryon bag and one personal item per person. The carryon bag must not exceed 22 inches long x 14 inches wide x 9 inches high. This carryon bag must be stowed in the overhead lockers on the aircraft. One personal item is also allowed. Personal items include a briefcase, purse, laptop bag, tote or book bag. This must not exceed total dimensions of 36 inches (length plus width plus height) and must fit under the seat.
Jet Blue
Jet Blue carryon baggage dimensions depend on what type of aircraft you are boarding, so check with the airline in advance. If your flight is being operated by an Airbus A320, the carryon bag dimensions are 26 inches long x 18 inches wide x 12 inches high. If you are travelling on an Embraer 190, the dimensions are 24 inches long x 16 inches wide x 10 inches high. With Jet Blue, you are also allowed a personal item not exceeding 17 inches long x 12.5 inches wide x 8 inches high.
Southwest Airlines
The Southwest Airlines website says its maximum carryon baggage dimensions are 10 inches x 16 inches x 24 inches. The airline also allows one other personal item per passenger. On its website, Southwest gives the following examples of personal items: "Purses, briefcases, cameras, food containers, or laptops including case."
Other items
Airlines do make allowances for adults travelling with babies, or passengers who need to carry vital medical equipment such as CPAP machines. The best course of action is to check the airline's website or contact its customer help line. Often, equipment needed by babies and medical items can be take on board in addition to the basic carryon baggage allowance.
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