When do girls typically reach menarche?

Menarche, the onset of menstruation, typically occurs around the ages of 12 to 13. This is an important milestone in female puberty and signifies the beginning of reproductive capability. The age at which menarche occurs can vary due to factors such as genetics, nutrition, and overall health.

Most research indicates that while some girls may start menstruating as early as 9 or as late as 16, the average onset is generally observed in the early teenage years, making the 12 to 13 age range the most widely accepted norm. This timing reflects a combination of biological development and individual maturation processes that occur during puberty. Understanding this age range helps in recognizing the physical and psychological changes that accompany adolescence in girls.