In males, the testicles, scrotum, and penis grow in size during puberty. Researchers say the average size of an erect adult penis is 5.1 to 5.5 inches in length, but that is just an average, and teens ...

If you have ever been concerned about your penis size, you're not alone. The size of the male sex organ has long been thought to be an indicator of a person's testosterone levels and sexual abilities.

This is the long and short of it. A female doctor says most people overestimate the size of the average penis, claiming most men barely measure more than five inches even when they’re rock hard. Dr.