Year 618 (DCXVIII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. The denomination 618 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities. The figure on the right illustrates the geometric relationship. Expressed algebraically, for quantities a and b with a > b > 0,