At what age do men typically start to masturbate?

Intrauterine: This behavior can be visualized on ultrasound prior to birth.

Intrauterine: This behavior can be seen on prenatal ultrasounds.

Pre-puberty: There is a difference between toughing one's penis as occurs inutero in infancy, and childhood and masturbation for pleasure, which occurs in early prepuberty in most males. Typically around 12 or 13 years old.