Checked baggage For domestic flights, bag fees vary and range from free to $200. Southwest Airlines is famous for its "Bags Fly Free" arrangement - they allow two bags for no charge. Yet, most airlines charge around $30 for the primary bag and $35 for the second bag. There has been a move in recent years by some airlines to include free baggage allowance (like the JetBlue model) with an upgraded seat. You can check with individual airlines to check whether they offer this advantage for booking a superior class of administration. Baggage fees are based on piece, size, and weight. Assuming that your bag is too enormous or too heavy, according to airline standards, you should pay extra fees. Bags that weigh in excess of 70 pounds usually fall into this category.