Airline Checked-in Luggage Size Restrictions

On most flights, the size and weight restrictions for a "standard" checked bag are pretty uniform. But as a la carte or "budget" pricing practices sweep across the industry, the rules have started to flex. Some airlines institute better baggage allowances for passengers who buy more expensive tickets or hold higher mileage plan status.

In a survey of five of the country's largest airlines, only one – Southwest Airlines – still allows two free checked bags for coach passengers. But if you're willing to pay the fee to check a bag – typically starting at about $25 per bag – many other airlines will let you check a suitcase through. The size allowance for those checked bags in coach are uniform across the airlines: Each bag can measure up to 62 linear inches and weigh up to 50 pounds. To calculate linear inches, add up the height, width and length of your suitcase. For example, if the suitcase measures 28 inches by 20 inches by 12 inches, that works out to 28 + 20 + 12 = 60 linear inches.

Although most U.S. airlines are dead serious about collecting your checked bag fees, they also allow a number of exemptions for frequent flyers, holders of their branded credit cards, and active-duty military members and their dependents. The following exemptions allow you to check at least one bag through for no extra fee, even if you're flying on a coach ticket:

• Loyalty programs: If you hold Premier Silver status or higher on United Airlines, Elite status or higher on Alaska Airlines, AAdvantage Gold status or higher on American Airlines (or oneworld Ruby status with their partner network), or Delta Medallion Status (or SkyTeam Elite status with their partner network), you can check a free bag through.
  
• Branded credit cards: If you hold an eligible American Express SkyMiles credit card and use it to book your ticket, you can check a free bag through on Delta Airlines. The same allowance applies to holders of an AAdvantage Aviator or Citi AAdvantage credit card on American Airlines, and holders of an Alaska Airlines Visa credit card.
• Active-duty military: Each of the airlines listed here allows active-duty military members and their dependents to check at least three bags through, free of charge. 
• Location-dependent travel: Alaska Airlines allows up to three free checked bags for tickets that involve travel only within the state of Alaska, and up to two free bags for Alaska residents enrolled in their Club 49 program, as long as the flight itinerary includes at least one Alaska city. 

The number of bags you can check at no charge soars with business or first class tickets. United, Delta, Alaska and American Airlines all allow at least one free checked bag for business or first class fares. Of these airlines, United, Delta and American also increase their weight allowance to 70 pounds per suitcase when you fly on a premium ticket. Watch the size, though – you're still limited to 62 linear inches.

For international flights, most airlines will allow at least one free checked bag up to the standard limit of 50 pounds and 62 linear inches, even on a coach ticket. This policy varies by airline and destination, so always check international baggage policies – and the seasonal restrictions that sometimes crop up – when you book your tickets.

If your suitcase weighs or measures more than your baggage allowance, you can probably still get it into the plane's baggage compartment – if you're willing to pay a fee that can easily run into the triple digits. There's an upper limit too: None of the airlines mentioned will accept suitcases that weigh more than 100 pounds on domestic flights; oversize or overweight baggage may be refused outright on some international flights, depending on both the airline's policy and that of the destination airport. Unless you're transporting statuary, suitcases full of books or anything similarly heavy, this is rarely an issue for domestic passengers.

Finally, each airline also imposes its own regulations for sizing and handling of oversize luggage, and some items measuring more than 100 linear inches may be refused outright. So always check the fine print if you're traveling with anything particularly large, heavy or bulky.

Tip

Now that you've measured and weighed your checked bag, remember to secure it with a TSA-approved lock.