It's common for men to have concerns about the size of their penis, but it's important to note that penis size varies significantly from person to person, and in most cases, what you're experiencing is likely within the normal range. Many factors can influence Small Penile Syndrome, and it's crucial to understand that size isn't the sole determinant of sexual health or satisfaction. just like height, eye color, and other physical traits, penis size is largely determined by genetics. Some men are naturally predisposed to have a smaller or larger penis. On average, an erect penis ranges from about 5 to 6 inches in length, but anything within the range of 4 to 7 inches is considered within the typical range.