At what age does the penis typically stop growing in males?

Penile growth typically concludes by the end of puberty, which for most males occurs between ages 14 and 18 years. Growth is driven primarily by rising testosterone levels during puberty and follows a predictable sequence: testicular enlargement usually begins first (around age 11–12), followed by penile lengthening and thickening, pubic hair development, and eventual attainment of adult genital morphology. By age 17–18, over 95% of males have reached their final adult penile size—both in the flaccid and stretched (non-erect) states—as well as full testicular volume. While minor individual variation exists—and rare cases of very delayed puberty may extend growth into early adulthood—penile size does not increase after epiphyseal closure of the long bones and completion of gonadal maturation. It’s important to emphasize that adult penile dimensions vary widely across healthy individuals and are not correlated with hormonal status, fertility, or sexual function once development is complete.