Carry-on luggage size restrictions vary by airline-here's how to tell if your suitcase, backpack, or duffle bag is small enough to bring as a carry-on.

Best for: a carry-on bag via Delta, United, American, JetBlue, Alaska, Southwest, and Allegiant Many major airlines — including Delta, United, American, JetBlue and Alaska — list 22-by-14-by-9 inches ...