The Average Bed Sizes

Twin Beds

• Twin size mattresses measure 39 by 75 inches. This size is ideal for one person. The size may not be long enough for some taller people; therefore the twin XL is available at 39 by 80 inches. Twin and twin XL mattresses are often used in children's bedrooms, college dorms, on bunk beds, daybeds and trundle beds. Two twin XL mattresses can be put side-by-side to create a bed the size of a king.

Full Beds

• Sometimes referred to as a double bed, the full size mattress is 54 by 75 inches. This was the most common size until the 1960s. It is gaining popularity in children's rooms. This size is most comfortable for people 5 feet 5 inches or less. Some find the full size bed too narrow for two people to comfortably sleep.

Queen Beds

• Today's most common size bed is the queen mattress, measuring 60 by 80 inches. Two people can comfortably use this size bed. These are ideal for moderately-sized master bedrooms and guest rooms. An appropriate frame and center support under the mattress should be used.

King Beds

• King beds can vary from 76 to 78 inches wide by 80 inches long. They are also sometimes referred to as standard or eastern king beds. These can be difficult to use in small rooms but provide ample sleeping space for two people. As with queen beds, all king beds require a frame and center support or the mattress will sag.

California King Beds

• California king, or western king, beds are 72 by 84 inches and are a good bed choice for tall people. These are most commonly found in western states. Bedding can be more difficult to find than standard king size, especially in eastern states, but can be easily found on the Internet.

Uncommon and Custom Sizes

• In addition to standard sizes, there are uncommon and custom sizes. A three-quarter bed measures 48 by 75 inches and is considered obsolete by most bedding manufacturers. The Olympic queen is slightly wider than the standard queen at 66 by 80 inches. Antique beds often require custom-size mattresses, which can be ordered from a number of mattress stores and also online.