A standard or eastern king bed is 76 inches wide and 80 inches long. A California or western king bed is 72 inches wide and 84 inches long. A standard king is approximately the same size as two extra-long twin beds pushed together.
A standard king bed is 16 inches wider and the same length as a queen bed, which is 60 inches wide and 80 inches long. A California king bed is 12 inches wider and 4 inches longer than a queen bed. Both sizes are wide enough for two adults to sleep comfortably. A full bed is 54 inches wide and 75 inches long. An extra-long twin bed is 39 inches wide and 80 inches long. A standard twin bed is 39 inches wide and 75 inches long.