Big Hands? Big Feet? What Actually Determines a Man's Penis Size

Men have worried that their penis is too large or too small for centuries. 

According to the Kinsey Institute, the average erect penis length is five to six-and-a-half inches, but many fall outside that range.

Dr. Curtis Brown specializes in FTM and MTF genital reconstructive surgery, and he told Broadly that penis size is in part hereditary.

"If you picture a bell curve [of penis size], you've got the 95 percent that are normal, and then you have 2.5 percent that are way too big and 2.5 percent that are way too small," Brown said. "The variation is definitely genetic. Hormones can also influence penis size. If there's fetal exposure to estrogen, that can have abnormal effects on the phallus—it could feminize the phallus. There's a lot of different things that can go wrong."

A majority of men have nothing to worry about; size variation is typical, and for the record, researchers have found that size has nothing to do with race.

"We get a lot of requests for [penis enhancements]," Brown says. "Usually from patients who are 'normal', but they're not happy with their size for one reason or another. Usually it's psychological. Maybe they had a girlfriend who told them they had an ugly penis, or they just always thought it's inadequate. It's all in their heads."

Source