are there different types of king size beds
In the mid-1950s, the United States bedding industry introduced a new size: the king size. A king-sized bed differs from the other sizes in implementation, as it is not common to have a king-sized box spring; rather, two smaller box-springs are used under a king-sized mattress. It is a common misconception that in a US ``standard'' or ``Eastern king'', the box springs are identical in size to a ``twin extra-long''; however, ``twin extra-long'' mattresses next to each other add up to 78 inches (200 cm) wide instead of the 76 inches (190 cm) width that is standard for an ``eastern king''. Another size variant in the United States is the ``California king'', which measures 72 by 84 inches (180 cm × 210 cm) long (narrower but longer than the standard king).
Bed