Wouldn't it be a nice and joyous world if the carriers had constant restrictions on the size and weight of carry-on bags? Well, your dreams are now squeezed like the mammoth execution you tried to fit into the trunk of your last flight. Not all airport storage is created equal. Each airline bases their package limitations on their internal configurations. Which means, in short, one bag could be transported on one flight but must be checked on another.
Fortunately, domestic airlines such as US Airways, Delta, American and United agree on their maximum size, 22 x 14 x 9 inches. Unfortunately, luggage with most wheels pushes these dimensions to the breaking point. Even I had to check a bag because the wheels were just too big for the overhead compartment to close.
A few domestic carriers are more generous with their bag restrictions. Alaska Airlines allows a full 24 x 17 x 10 inches (so passengers can fit in their parks on board, we assume). AirTran and Southwest allow 24 x 16 by 10 inches. Unless you carry bricks, transports are rarely weighed, but there are technical limits. Make sure your carry bag does not exceed 40 pounds on the big wig airlines and 25 pounds on the not so big wig airlines.
If you are abroad, wear a backpack or a light clamp duffel. European carriers have extremely strict design dimensions. Weight is also a big factor. Air France and Alitalia limit transport to 21 x 13 x 9 inches with a maximum weight of 26.4 pounds. Carry-on bags at Lufthansa, Swiss and Turkish may be 21 x 15 x 9 inches, but these airlines are counter-attacking with a maximum weight of 17.6 pounds.
New seats and floats often mean less than eight inches of space for bags under the seat in front of you with a maximum width of 14 inches. The middle seat in a three-seat row has even less space under the seat.
Our advice, if you know you are going abroad or traveling in different sized planes, it is worth buying a lightweight, smaller carrying capacity around 21 X 13 X 9 inches. A bag of that size flies almost everywhere if you don't fill it with heavy, unforgivable items. Keep in mind that household boxes are not "very" flexible, so be sure to measure your execution before pulling it all the way to the gate, only to be forced to check it.