Normal penis size for 16. Visit our Men's Health category page for the latest news on this subject, or sign up to our newsletter to receive the latest updates on Men's Health. 01.05.2018 Tukree European Urology. We use cookie information or information provided by yourself upon a purchase or filling in a form. The researchers said the self-reported erect penile dimensions were consistent with findings from other studies. As much as 45 percent of men believe they have a small penis. A flaccid penis can change in size temporarily due to external factors, such as temperature. Researchers publishing in the Journal of Urology studied the penis sizes of 80 "physically normal" men, measuring penile dimensions before and after drug-induced erections. Baltimore, Md.: Girth Measurement Tape amazon.