At the age of twelve, how big should a boy's penis be?

Patient's question:

No

Doctor's answer:

Hello, according to your description, it's normal. You're still young, don't worry. After the age of 18, as long as the hardness is not a problem, don't worry. When not erect, it's greater than 3.5 cm, and when erect, it's greater than 10.5 cm, which is normal.