Menopause ends after a woman has been without her period for 12 consecutive months, states WebMD. On average, women enter menopause around age 51, but they cannot consider themselves to be done with menopause until they haven't had a menstrual cycle for 12 months.
Menopause is broken into three stages, according to WebMD. The first stage is known as perimenopause. During this stage, a woman's menstrual cycle may become irregular. The second stage is known as menopause, and it starts as soon as a woman stops having periods. After her periods have stopped for 12 months straight, she enters the third stage, which is known as postmenopause. This third stage lasts for the rest of her life.