Oct 25, - You can get an esitmate of how "average" you are compared to teen peers. Your penis size for erect position (hard). A. 8"+. B. "". C. Feb 11, - It's normal at your age to be concerned about size, but don't sweat it. It will be what it will be. Nothing you can do (including worrying) will make your penis is the average size of a penis for a year-old? I'm 13, and.