Length of man’s penis relative to index-ring finger ratio

A male adult has a longer penis when he has a ring finger longer than index finger or when the “digit ratio” is smaller, according to recent research.

“Digit ratio” refers to the ratio of the length of the second finger or the index finger to the fourth finger or ring finger of the right hand.

A research team led by Prof. Kim Tae-beom of the Gacheon University Hospital released its paper on the subject on the Asian Journal of Andrology on July 7.

Fetuses are influenced by different amounts of male hormones, and it is commonly known that the amount of exposure to male hormones influence the length of fingers.

“I hope to have this experiment help our understanding on the formation of both male reproductive organ and the human hand,” Prof. Kim said. He even suggested that this experiment may be significant evidence that will help us understand human fetal development.

The research conducted by the team had an average penile length of 11.7 cm, ranging from 7.5 cm to 17 cm. With examination of total 144 men aged 20 years or older, they have reached the conclusion that there was a visible relationship between the “digit ratio” and penile length.