As of 2015, the three major U.S. airlines have identical carry-on bag size restrictions, but discount airlines and international airlines have different limitations. Delta, American, and United all require that carry-on bags be smaller than 22 inches long by 14 inches wide by 9 inches tall.Continue Reading
Southwest Airlines and JetBlue allow for larger carry-on bags that measure up to 24 by 16 by 10 inches. Lufthansa requires that carry-on baggage be smaller than 22 by 16 by 8 inches. In addition to size restrictions, some airlines limit the weight of carry-on baggage.
Besides size, other restrictions apply to carry-on baggage due to Transportation Security Administration rules that forbid weapons, liquids and other potentially dangerous items. These rules apply to all flights within the United States, regardless of airline.Learn more about Geography