Viagra. or ask your doctor
Anywhere between 5 and 8 inches erect...
If you are 13, the normal length of your penis should be between 4 and 5 inches.
It should be around 3-6 inches but, if your penis isn't around that don't worry it will grow.
The average is between 5 and 7, so don't worry
it SHOULD be about 5 inches. I AM 13 and mine is 6.5inches
5-6 inches
The average adult male's penis is between 5 and 6 inches.
10 inches.
The average for a adult male is 5-6 inches.
Long enough to urinate successfully.
An erect adult penis averages 5-5.5 inches in length. If your penis is already 8 inches long, I would assume it has reached its maximum growth.
about 5 3/4 inches