Mattresses are measured in inches, width by length. Common mattress sizes include twin, twin extra-long (XL), full, queen, king and California king, explains the Better Sleep Council. Mattress heights vary by product, according to Serta.
A standard twin size mattress is 38 inches wide by approximately 75 inches long, states the Better Sleep Council. A twin XL is also 38 inches wide, but it is several inches longer than a regular twin. It is commonly used in dorm rooms and is a solution for sleepers who are too tall for a regular twin.
A full mattress, sometimes called a double, is 53 inches wide by roughly 75 inches long. As with a regular twin, a full is too short for some adults, men in particular, says the Better Sleep Council. A queen mattress measures 60 inches wide by 80 inches long, providing an addition 6 inches in width and 5 inches in length compared to a full.
A king-size mattress is 76 inches wide by roughly 80 inches long. This is about the same size as two twin XL beds pushed together, notes the Better Sleep Council. A California king mattress, measuring 72 inches wide by 84 inches long, is narrower than a regular king, but provides an additional 4 inches of length.