Airline Baggage Rules Southwest is known for its customer-friendly baggage policies. Passengers can check up to two bags for free, with each bag weighing up to 50 pounds and measuring a maximum of 62 inches in total dimensions. Overweight (51-100 pounds) or oversized (over 62 inches) bags incur a $75 fee each. For carry-on, Southwest allows one bag up to 10 x 16 x 24 inches and one personal item, such as a purse or laptop bag, which must fit under the seat. Special items like strollers, car seats, and sports equipment are also accepted, often without additional charges.