Southwest Airlines allows one carryon bag per passenger, measuring no larger than 10 x 16 x 24 inches (including handles and wheels). This is smaller than most U.S. carriers, which typically allow 9 x 14 x 22 inches.
Southwest's carryon bag size limit applies to the entire bag, including wheels and handles. The airline enforces this strictly at the gate, not at check-in. If your bag exceeds the limit, you'll be charged a checked baggage fee ($30-$75, depending on when you pay).
Unlike many airlines, Southwest doesn't offer a personal item allowance beyond the carryon. Your carryon must fit in the overhead bin; if it doesn't, you'll be asked to check it.
Most standard rolling carryon suitcases meet Southwest's size requirements. Some popular models include:
If your carryon exceeds 10 x 16 x 24 inches, Southwest will charge you a checked baggage fee. Fees start at $30 if paid online before departure but rise to $75 if paid at the gate. This policy applies even if you're flying with a companion pass or have a boarding pass for the same flight.
To avoid fees, measure your bag before arriving at the airport. Use a tape measure or a measuring tool available at most luggage stores.
Many travelers assume that soft-sided bags automatically comply with size limits. However, some soft-sided bags can expand beyond the allowed dimensions when packed. Always measure your bag when fully packed to ensure compliance.
I once saw a passenger at Denver International Airport forced to pay a $75 fee because their seemingly small soft-sided duffel exceeded the limit when packed. Double-checking measurements beforehand could have saved them $75.
If you need to check a bag, Southwest's checked baggage size limit is 10 x 16 x 24 inches (same as carryon) but with a maximum weight of 50 pounds. Excess weight fees apply for bags over 50 pounds. For more details, see our guide on checked baggage size limits.
Southwest's policy aims to ensure efficient boarding and maximize overhead bin space. By adhering to these guidelines, you can avoid unexpected fees and ensure a smoother travel experience.