A standard full-size mattress measures 54 inches wide and 75 inches long. This type of bed is also referred to as a double bed or a standard bed. It commonly sleeps two adults.
Although many single people and couples choose full-size mattresses, many people prefer the greater amount of sleeping space afforded by queen- and king-sized mattresses. A queen mattress measures 60 inches wide and 80 inches long, while a king mattress measures 76 inches wide and 80 inches long. Twin mattresses are generally chosen for children, since they sleep just one person and take up less space, measuring 39 inches wide and 75 inches long.