Twin Vs. Full Mattress Dimensions

Length

• Both twin and full-size mattresses are 75 inches long, making them 5 inches shorter than king- and queen-size mattresses.

Width

• A twin-size mattress is 39 inches wide, while a full-size mattress is 54 inches wide.

Depth

• The depth of twin and full mattresses vary, with style being the primary factor; for example, a pillow top mattress will be larger than a firm mattress. Twin and full mattresses can range in size from 5 to 20 inches deep.

Variations

• Both twin and full-size mattresses are available in extra long models, which are 80 inches long--the same length as queen and king mattresses. In these models, both sizes retain their normal width.

Exceptions

• While twin and full-size mattresses are common among innerspring, air, foam and soft side waterbed mattresses, they are almost unheard of with wood frame waterbeds. Instead there are super single mattresses, which are 48 inches wide and 84 inches long, and queen size, which are 60 inches wide and 84 inches long.