Puberty: From Child to Adult Body Timeline

Puberty: From Child to Adult Body 18

Age 10½ (8–13) Breasts begin to develop Puberty Thelarche, usually the first visible sign of puberty in girls. Normal range 8 to 13.
Age 11 (8½–13½) Pubic hair appears Puberty Pubarche, caused by hormones from the adrenal glands and ovaries. Normal range 8½ to 13½.
Age 11¼ (10–12½) Growth spurt Puberty Girls grow fastest at about 11, sometimes 8 to 10 cm in a year. Normal range 10 to 12½.
Age 11½ (9½–13½) Puberty begins: testes enlarge Puberty Gonadarche, the first sign of puberty in boys. Normal range 9½ to 13½.
Age 11–12 Grey matter peaks Puberty The volume of grey matter in the brain peaks around the start of puberty, slightly earlier in girls.
Age 12 (10–14) Pubic hair appears Puberty Pubarche in boys. Normal range 10 to 14.
Age 11–13 The 12-year molars Puberty The second permanent molars come through, between 11 and 13.
Age 12½ (10½–14½) First period Puberty Menarche, the major landmark of puberty in girls. Normal range 10½ to 14½. In the 19th century the average was around 15.
Age 12–13 Last milk tooth falls out Puberty By about 12 or 13 all 20 milk teeth have been replaced.
Age 13 (11–15) Growth spurt Puberty Boys grow fastest at about 13, two years later than girls, and longer. Normal range 11 to 15.
Age 13 (11–15) Spermarche Puberty The testes start producing sperm, the major landmark of puberty in boys. Normal range 11 to 15.
Age 13+ The body clock shifts later Puberty Teenagers get sleepy later in the evening and need more sleep than adults, a biological shift.
Age 13–15 The voice breaks Puberty The larynx grows and the voice drops by about an octave, usually between 12 and 15.
Age 15½ (14–17) Adult height reached Puberty Growth plates close and growth stops. Normal range 14 to 17.
Age 15½ (14–17) Wisdom teeth Puberty The third molars come through, if they come through at all. Normal range 14 to 17.
Age 17 (15–19) Growth is complete Puberty Boys end up about 13 cm taller than girls on average. Normal range 15 to 19.
Age 17 (15–19) Wisdom teeth Puberty The third molars come through. Normal range 15 to 19.
Age 20–25 The prefrontal cortex is still maturing Puberty The part of the brain for planning and self-control keeps developing until the mid-twenties.