The size of a cabin suitcase can vary depending on the airline. However, most airlines have a standard domestic carry-on luggage size of around 22 inches tall, 9 inches deep, and 14 inches wide. The combined dimensions of carry-on baggage should be less than 45 inches, with individual items measuring no more than 22 x 14 x 9 inches. Some airlines allow larger bags to be carried on, while others have more strict size requirements. For example, Hawaiian Airlines allows a total linear size of 45 inches and JetBlue Airways allows 22 x 14 x 9 inches. It is important to check with the airline for their specific carry-on luggage size restrictions before traveling.