It's important to know what you're getting into when deciding between checked or carry-on bags for your next trip. The U.S. Department of Transportation defines checked bags as those that you allow the airline to handle before boarding. Carry-on luggage, on the other hand, are those bags you carry with you and place under a seat or in the overhead bin of the cabin. While the actual difference between the two types of luggage is quite simple, the implications of choosing one over the other can affect your travel budget and the convenience of your trip.
If taking a long trip, checked bags may be the best choice. Much larger bag sizes are allowed, compared to carry-ons, although most airlines charge for checked bags. As of March 2011, most major airlines were charging between $15 and $35 for the first checked bag with additional charges for two or more bags. Overweight bags, typically those in excess of 50 lbs, or oversized bags, usually those over 62 total linear inches, can carry significantly higher fees.
While carry-on bags meeting the right size requirements are typically free, there remain certain restrictions that require preparation. The Transportation Security Administration (TSA) limits the quantity of liquids or gels that may be carried onto an airplane. As a simple rule, they recommend that each passenger only carry containers that hold 3 ounces or less in a single, clear 1-quart-sized, plastic bag. Be prepared to quickly remove this quart-size bag, along with other objects like laptops, to be placed in security bins at security screening checkpoints.
There are certain items that you may pack in your checked bags, but not in a carry-on. As of 2011, sharp items such as box-cutters, knives and swords were allowed in checked baggage. Additionally, certain sporting goods such as bats and and gold clubs as well as ammunition and firearms were acceptable with specific declaration procedures and some additional prohibitions. Most flammable or explosive items and disabling chemicals were not allowed in either carry-on or checked luggage.
While many travelers opt for the more cost-effective method of carry-on baggage, this also means that space in overhead bins fills quickly. If no room is left by the time you board, the airline could require you to check your carry-on bags. Some airlines, in anticipation of a full flight, will ask for volunteers to have their carry-on bags checked prior to boarding free of charge. This can be a way to check small bags without the concern of finding precious on-board space, but don't count on it.