The standard length of the penis is related to race and geography, with the length of the adult penis ranging from 4.5 to 8.5 centimeters in the flaccid state and 9 to 16 centimeters when erect. Penile length refers to the length of the stretched penis, which needs to be determined according to strict rules, is to put the penis in the stretched state, along the back of the penis to measure from the pubic symphysis to the tip of the glans obtained from the length of the penis (excluding the length of the foreskin) for the length of the stretched penis. It should be noted that in obese children, the adipose tissue above the pubic bone should be pushed away as much as possible to make the results accurate. Due to racial and geographic differences, there is no standardized penile length, and reports vary widely. Adult penile size varies, in most cases ranging from 4.5 to 8.5 cm in the flaccid state, and up to 9 to 16 cm in length when erect.