For consumers on the west coast, there is also the "California King Mattress" which is approximately 72 inches wide by 84 inches long – 4 inches narrower and 4 inches longer than a regular king.
The king size mattress dimensions are 76 inches wide by approximately 80 inches long – about 18 inches wider than a queen. This is the closest a couple can come to having as much personal space (38 inches) as each would have on a twin bed.
Queen mattress dimensions are 60 inches wide by approximately 80 inches long – 6 inches wider and 5 inches longer than a full size mattress. These added inches can make all the difference in comfort, especially for couples, and have made the queen size mattress today's most popular mattress size.
A twin mattress is the smallest possible mattress size, other than a crib-sized mattress. Twin mattress dimensions are approximately 38 inches wide by 75 inches long. Both twin and full sizes are approximately 75 inches long, which may be too short for some adults, especially men.
Sometimes still called a double mattress, a full size mattress is 53 inches wide, which is just 15 inches wider than a twin size (single). That leaves each partner only 27 inches of personal space, or about the width of a crib. Both twin and full sizes are approximately 75 inches long, which may be too short for some adults, especially men.