What is the difference in a King size and Cal-King size mattress?
There are two sizes of King mattresses. California King and Eastern King. Eastern King is the older and more common of the two sizes. California King is very popular in California, declining in popularity as you move east toward the Mississippi river. East of the Mississippi we see customers buying Eastern King sizes. West of the Mississippi, King Size sets are often assumed to be California King. East of the Mississippi, King sets are often assumed to be Eastern King. Eastern King is the most common of the two sizes and the original King size.
