Sexual Development of Boys

For most boys, sexual maturation begins at about age 11 to 13, as the testes and scrotum experience an initial enlargement.

Often the growth of testes is often accompanies or soon followed by the appearance of pubic hair.

About six months to a year later, the penis undergoes a period of rapid growth that happens about the same time as a general growth spurt.

By the time the penis is fully developed – often around 15 years – a boy reaches puberty and is now capable of fathering a child.

Facial hair tends to grow later. A moustache may first grow at the upper lips and then spread to the upper cheeks and finally to the chin. Body hair also begins to grow, although with some boys, chest hair may not appear until the later teens or early twenties, if hair appears at all.

During adolescence, boys’ voices change to the low tone of an adult male.