At what age does menstruation typically begin?

Menstruation begins when a woman is just a girl. Some girls begin menstruation, or start getting their periods, as early as 8. Others don't begin until the age of 15. For many girls, the appearance of breast growth, sometimes called breast buds, indicates that menstruation will begin with 2 years. The average age for the beginning of menstruation in the United States is 12.