Men's erect penis size depend on method of arousal

The average American man's penis is 5.6 inches (14.2 centimeters) long when erect, a new survey of 1,661 men finds. The study, published online July 10 in the Journal of Sexual Medicine, is relatively consistent with the results of prior surveys of penis size.

In the new study, Debby Herbenick, a researcher at Indiana University, and her colleagues asked 1,661 men to measure their penis's length and girth for the purposes of fitting for a condom. (The men submitted their data online.)

At the time of their measurement, some men were with partners or "a friend," although most employed a DIY method for attaining an erection. Moreover, all erections are not created equal, the study also found.

Different methods of obtaining an erection may lead to different size measurements — men in the study who became aroused through oral sex reported larger penis size on average than those who attained erections through fantasizing, Herbenick said. "We don't know if that means that when men have oral sex that it's more arousing and they get a bigger erection, or means that men who have bigger penises could be getting more oral sex in the first place," Herbenick told LiveScience.

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