Several baggage retailers, such as eBags and Luggage Pros, post online charts of maximum carry-on luggage sizes for many of the major airlines. Individual airlines, such as American Airlines, also typically post their carry-on size restrictions on their websites.
The most common size limit for flights within the United States is a total of 45 linear inches and 40 pounds. International flights may have different requirements, so customers should check with the airline to confirm. To determine the linear measurement of a bag, add together the height, width and length. All wheels and handles are included in the measurement. One common bag measurement that meets this requirement is 22 inches by 14 inches by 9 inches.