A king-sized bed may have a king-sized box spring (bed base), or two smaller box springs under a king-sized mattress.
Bed size standards vary around the world. Not only are the names of the standard sizes sometimes different but even beds and mattresses with the same name can have different measurements in different countries. Even within a single country different manufacturers interpret the "standard" bed sizes differently. Some might shave a couple of inches off to reduce cost, others add a little for comfort. Those few inches can make a lot of difference.Beds are usually labeled according to the dimensions of the mattress - the actual measurements of the bed itself might be a little wider and/or longer. A Standard King is also called an Eastern King and a California King is also called a Western King. A Standard King is about 4" wider and a California King is 4" longer.
Two people sleeping in a King size bed will get the same amount of personal sleeping space as in a Twin bed. In fact, if you pushed two Extra-Long Twin beds together they'd be about the same size as an Eastern King. For great versatility in a guest room, if you have the floor space, use 2 extra long twin beds separately for singles or push them together to make a king bed for couples
Beds/mattresses are often available also in extra long 220 cm (87 in) length. When buying sheets, you have to be careful to purchase the right size. Flat sheets will fit both sizes of King Beds, but fitted sheets are cut to fit one or the other. Before you go shopping for sheets, be sure to measure your bed exactly to be sure to buy the linens that will fit exactly.
Standard King or Eastern King Beds
These are about 16" wider than a Queen bed and the same length. A King size bed is sold with two box springs or frames and one mattress. This makes it easier to move.
California King or Western King Beds
These are 12" wider than a Queen and 4" longer. This is the longest bed commonly available in stores and is the best choice for tall people. Like the Eastern King, the California King bed set comes with one mattress and two half-width box springs to be more manageable when moving. Very tall single people can sleep from corner to corner and still be comfortable.
