suitcase in overhead luggage storage airplane carry-on bag packing
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Air travelers with carry-on luggage must clear a number of hurdles before getting on a plane: Does your bag meet the airline’s size guidelines? Are you complying with TSA rules?

Many travelers have experienced the sometimes heartbreaking choice of whether to discard something (a jar of grandma’s applesauce, a brand new bottle of fancy sunscreen) at security — or pay the price to check a bag. Others have wheeled up a suitcase that, on all previous occasions, they’ve been able to carry on, only to be sent back to the airline counter.

Over the last decade, as an increasing number of U.S. airlines began to charge economy travelers for checked bags, more and more people flying by plane do so exclusively with carry-on luggage. But with size guidelines that vary by airlines, and TSA rules that change not infrequently, it can be difficult to breeze through security (even with your chic new carry-on backpack).

Check With TSA

Rules change, and vary between airports, so make it a habit to check the TSA website for guidance before you pack. (Grandma’s applesauce does, unfortunately, count as a liquid.) However, only packing liquid containers that can contain up to 100 milliliters (3.4 ounces) or less is a good habit to get into. The total amount of liquid container capacity on any checked bag should not exceed one quart. (A quart-sized plastic bag can help you stick to this rule.)

Remember, TSA rules measure container size, or capacity, rather than the actual amount of liquid inside any given container. Even if your nine ounce shampoo bottle only contains an ounce of shampoo, it still needs to be checked, discarded, or left at home.

Check With Your Airline

Unfortunately, there are no standard guidelines for carry-on size or weight, and the range of what airlines allow is surprisingly broad.

Virgin America’s carry-on policy, for example, allows suitcases measuring up to 24 inches long, 17 inches wide, and 10 inches deep, and weighing no more than 30 pounds. Frontier Airlines, Spirit, and Southwest permit carry-on bags that are 50 linear inches, while Alaska has increased that limit to 51 linear inches.

Volaris, on the other end of the spectrum, only allows bags under 15.7 inches long, 15.7 inches wide, and 9.8 inches deep as free carry-ons.

Most often, travelers will see carry-on size restricted to 22 inches long, 14 inches wide, and 9 inches deep. That's a standard 45 linear inches adhered to by legacy carriers like Delta and United.

Before you pack your suitcase — and, better yet, before you even buy a suitcase — check the carry-on size restrictions of your preferred airlines, and proceed accordingly.