when does your penis stop growing

The penis typically stops growing at the end of puberty, which is usually between the ages of 18 and 21. Penis growth begins during early puberty, around ages 9 to 14, and most significant growth happens between ages 12 and 18. While some minor growth changes may continue into the early 20s for a few individuals, by the late teens to early twenties, the penis generally reaches its adult size. After puberty, penis size remains stable, although it can change in size due to factors like erectile function as men age.