As the convenience of checked baggage diminishes even as the cost skyrockets to check your luggage, most people now opt to use the “carry on” baggage rules and bring a small suitcase on board the aircraft, usually along with a large purse, backpack, or laptop bag. Careful packing and planning means that most people who don’t require a new outfit every day can fairly easily fit everything they need – even for a trip of a week or more – in their carry-on luggage.
For most airlines the dimension of a carry on are 45 inches in total – meaning you simply add the highth, width, and depth of the bag. For example a bag with dimensions 12x12x21 should be OK as well as a bag of 14x14x 17 inches. Technically any airline can can reject bags for many reasons, but in practice you are going to be just fine sticking with the 45 inch rule and probably even fudging a bit over these measurements. However bringing large bags may get you some glares from the other passengers as you stuff your oversized luggage into “their” bin. A major challenge of flying now is that with so many carry on luggage folks using the overhead bins, there is little or no extra room in those bins or under seats. Often the carry-on bags need to be stowed in bins away from your seat or handed over to flight attendants, slowing the boarding process.
It is surprising to me how poorly organized the baggage and boarding process has become – I’d suggest to the airlines that more effective use or design of the overhead bins is immediately in order. Flight attendants, for example, know how to most efficiently stow bags yet they generally are not helpful as flyers tug, push, crunch and smash their and other bags into the dwindling available spaces. Another innovation might be to redesign the bins or bin doors so they can hold more, or find ways to use the massive cargo space that must now exist below as flyers increasingly turn to carry on options rather than checking bags.
Another aspect of Carry-on rules are “Prohibited Items”. Generally for that you’ll want to observe the 3-1-1 rule we discussed earlier. More details are here at the TSA Transportation Security Administration‘s official site. The link takes you to the “prohibited items” section.