Double-size beds, also called full-size beds, are not the same size as a twin bed, also called a single bed. Double beds are 15 inches wider than twin beds, but the length of both beds is 75 inches, which is 5 inches shorter than a queen-size bed.
Twin beds are 39 inches wide by 75 inches long. These beds will sleep one person comfortably. There is more sleeping space for one person. Twin beds are generally used for children's rooms, hideaway beds and daybeds. Taller people may have problems with the bed being too short. Twin beds are made for one person only and will not fit two people comfortably.
Double beds are 54 inches wide by 75 inches long. When two people sleep together on a double bed, each person has 27 inches of sleeping space, which is less room than what one person has when sleeping in a twin bed. Most people will find a double bed is not comfortable for two people because of the small sleeping area when two people occupy the bed. Taller people will find the bed is too short.
The bedding for a twin-size bed generally costs less than what the bedding for a double bed costs, which is still less expensive than queen-size bedding. Fitted sheets for a twin bed are 39 inches by 75 inches. Flats sheets for a twin bed are 66 inches by 96 inches. Twin bed sheet sets come with one pillowcase that measures 20 inches by 30 inches. Flat sheets for a double bed are 80 inches by 94 inches, while fitted sheets are 54 inches by 75 inches. Double bed sheet sets come with two pillowcases measuring 20 inches by 30 inches.
Twin bed box springs and mattresses are easier to fit around sharp corners and up narrow stairways because the width is only 39 inches. Double box springs and mattresses are more difficult to maneuver around sharp corners or go up stairways with lower ceilings because the width is 15 inches greater than that of a twin bed.