A California king bed is 4 inches longer and 4 inches narrower than a European, or regular, king bed. It is typically 72 inches wide by 84 inches long whereas a regular king-sized bed is 76 inches wide by 80 inches long. A king bed is considered the ideal size for a couple due to its width; the width is equivalent to two extra-long twin beds pushed together.
A European king bed is also called an eastern king. It is actually the same length as a queen bed. California kings are better choices for couples where one or both person is tall and requires extra length.