Our New Penis Size Study: Data from 1,661 Men in the United States

A new research study from our Indiana University research team was published online today in the Journal of Sexual Medicine. Its title? Erect Penile Length and Circumference Dimensions of 1,661 Sexually Active Men in the United States. Here’s a bit about our study:

Did we really measure the erect penises of 1,661 men in the US? 

No, we did not personally measure men’s penises. Rather, like many studies of penis size, we relied on men to report their penis size.

Were we concerned that men would lie about their size? 

Most people are honest – including in sex research studies. Also, men didn’t have any reason to lie to us. In fact, unlike most previous studies of self-reported penis size, they had good reason to report accurate data to us because we were using their size data to match them to a condom that was sized to fit their erect penis. If they reported a bigger-than-reality size to us, they would get a baggier condom. If they reported a smaller-than-reality size to us, the condom would be too tight.

So what did we find? 

Well, for people who care about penis size averages (and many people do, based on the questions I receive from readers through Kinsey Confidential and my other work), we found an average erect length of 14.15 cm and an average erect circumference of 12.23 cm as can be seen in the abstract of the article on the Journal of Sexual Medicine’s website. Personally, however, I am more interested in the broad range of penile sizes than only the averages. For those reading the full article, you can find the distribution of reported sizes in Table 3 of our article. There you will note that men in our study had erect penis lengths of 4 to 26 centimeters and erect penis circumferences of 3 to 19 centimeters. We also found that reported size varied by how men got the erection that they  measured. For example, men who received oral sex as part of the measurement process reported a greater erect length and circumference than other men. Is that because oral sex is more arousing to men and thus they have larger erections than they do from other sexual behaviors (e.g., self-masturbation with hand or hand stimulation from a partner or fantasy only, etc) or is it is that men who have a larger erect penis are more likely to receive oral sex from a partner (or more regularly)? We cannot tell from these data.

If you’d like to learn more about research from our team at the Center for Sexual Health Promotion at Indiana University – including opportunities to participate in future research studies – you can fill out this online form to be added to our mailing list. To receive a copy of the full article from our penis size study, email us at cshp (at) indiana (dot) edu. 

 

About Dr. Debby Herbenick

Dr. Debby Herbenick

Dr. Debby Herbenick is a sex researcher at Indiana University, sexual health educator at The Kinsey Institute, columnist, and author of five books about sex and love. Learn more about her work at www.sexualhealth.indiana.edu.