Penile length and circumference: a study on 3,300 young Italian males

The knowledge of normal variations in the size of male external genitalia is of considerable interest to several disciplines. We carried out an extensive study in young Italian males to provide estimates of normal variations of penile dimensions.

The penile length in flaccid and stretched states and the penile circumference were measured in a random group of 3,300 young men aged 17-19 years and free from endocrine disorders and from congenital or acquired abnormalities of the penis. In a random sample of 325 subjects of the same set of people, penile length and circumference were also correlated with weight and height. Statistical analysis was performed with the Sperman test, because our data were not normally distributed as tested by the Kolmogorov-Smirnov test (p < 0.01).

The median values of penile dimensions recorded in the present study are flaccid length 9.0 cm, flaccid circumference, at the middle of the shaft, 10.0 cm, and stretched length 12.5 cm. We also observed that the penile dimensions are highly correlated with height and weight.

Since penile length and circumference correlate with anthropometric parameters such as weight and height, we suggest to consider themselves as two bodily measures which display a wide extent of normal variability along the general population.