Pull out the measuring tape before you decide what to carry on. Most airlines will require your carry-on luggage to be no larger than 22 inches long by 14 inches wide by 9 inches tall. The Federal Aviation Administration recommends ensuring your carry-on bag is no larger than 45 linear inches, which is the total of its height, width and depth. At most airports, you can find signs that demonstrate the dimensions of appropriate carry-on luggage size, and you can even test your bag by placing it in a metal basket provided to see whether it will fit. Most carry-on luggage is placed in the overhead bins, but if you have a tote bag or a duffle bag, you might be able to fit it under the seat in front of you.
Airlines will typically not weigh your carry-on luggage, but most of them expect that what you bring on the plane will not weigh more than 40 pounds. If you cannot lift your luggage over your head, as you will need to do when stowing it in overhead bins, it is probably too heavy to carry on, and you will need to check it. The FAA recommends stowing heavier items under the seat instead of overhead, to prevent injuries in case the heavy luggage falls.
In addition to one piece of carry-on luggage, airlines will also allow you to bring a personal item onto the plane. For most people, the personal item is a purse, a laptop, a briefcase or a backpack. American Airlines, for example, requires the personal item to be no larger than 36 linear inches and able to fit under the seat in front of you. Airlines want to reserve the overhead bin space for larger carry-on pieces. Sliding your personal item under the seat will also give you better access to it in case you need it during the flight.
If you know you do not want to check a bag, make sure you pack one that is made for carry-on purposes. Most small roller suitcases fit the required carry-on dimensions, and there are garment bags that fold up to meet the size requirements as well. Remember, there are some benefits to checking your luggage, especially if you have a problem packing light. Also, when you check your luggage and have only a personal item to carry onto the plane, some airlines will allow you to board before the passengers who will be fighting for overhead bin space.
