Circumcision - Does it Affect Penis Size?

Length when erect:

Average erect penis length was 16.0 cm (95% CI 12.2-19.8) in 156 White men aged 18-55 years (mean 33) in Sydney, Australia [Richters et al., 1995]. Length in the 102 who were circumcised was 0.8 cm (5% or 1/20th) less than length in the 43 who were uncircumcised. It was suggested that "insufficient residual foreskin in some uncircumcised men may have tethered their erections". There are at least two interpretations of these data. (1) The tethering suggestion needs to take into consideration the type of circumcision the men had decades before. Given their age and the time of the study (early 90s) they would have been circumcised in the 1970s or earlier. At this time infant circumcision was done in Australia by use of bone-cutters, and gave a very tight circumcision with no loose skin, even when the pen is was not erect, i.e., most or all of the foreskin would have been removed. Circumcision of infants these days in Australia is for about 70% of infants by use of the Plastibell technique, which gives a "looser" circumcision, so no tethering would occur, so should not affect length of the erect penis when the male becomes an adult. (2) A more likely scenario is that because the men in the study measured their penis themselves, and a proportion of uncircumcised men have a foreskin that extends beyond the penis even when it is erect, they included this extra skin in the measurement they made. This would lead to an over-estimation, when in reality, for juts the penis itself, the length might not differ. The senior author on this paper in fact told me that they attempted to employ a sex worker as a research assistant to take the measurements, but this didn't end up working out so they had to allow the men to do it themselves.

Circumference of the erect penis:

• At the base - 13.5 cm (95% CI 10.7–16.2)

• Shaft just below coronal ridge – 12.4 cm (95% CI 10.0–14.8)

• Glans – 11.9 cm (95% CI 9.6–14.2).

Thus there was no significant difference between the circumcised and uncircumcised.

PS: The author notes that the means of all of the dimensions above are the same as the those for his own measurements, except for his glans, which has a circumference of 13 cm.