Typical airline size restrictions for carry-on luggage are 22 inches in length, 14 inches in width and 9 inches in height. Alaska airlines allows carry-on luggage of 24 inches by 17 inches by 10 inches, while some smaller, regional airlines require carry-on luggage to fit beneath the seat in front.
American Airlines, Delta, JetBlue, United and US Airways are all examples of airlines that impose the typical size restrictions for carry-on luggage, with Avienca quoting an overall size limit of 45 inches. These carriers also permit one additional carry-on item for personal use, such as a purse or laptop case, and have no weight restrictions. Some carriers impose weight restrictions in addition to size limits; for example, Hawaiian Airlines requires carry-on luggage to weigh no more than 25 pounds.