The Size of the Foreskin

The statement, “the size of a foreskin is equal to half of the skin on a penis,” is often used to justify never circumcising an infant. It is stated here as 50 percent of a penis’s skin but in his famous and often-quoted article, “The Case Against Circumcision,” that appeared in 1997, in Mothering magazine, Dr. Paul Fleiss stated that “the true length” of a foreskin is twice the length of its external fold and comprises as much as 80 percent or more of the penile skin covering.

Still another source puts the proportion at the opposite end of the spectrum, stating that the foreskin is never more than 16 to 18 percent of an adult male penis. So, which is the accurate statement? Plus a little more about size.

Understanding the calculation and its results

Those who come up with the larger portion tend to arrive at their proportion by adding the square inches of both the foreskin’s outer skin and its inner lining. In other words, they are doubling the square inches that someone only measuring the outside of the foreskin would get. In a sense, this is a somewhat subjective decision since the inner lining does have special functions such as providing lubricant to slide off the glans more easily and to slide into a vagina more easily.

Another conflict with the calculation is that the foreskin size can vary from male to male. For example, in some men, especially those with longer penises, the foreskin not only covers their glans, but it extends past it, sometimes as much as an inch or so past it. (One argument for not removing it, in fact, is that removing a lengthier foreskin makes the penis look shorter!) On other men, especially those with somewhat shorter penises (3 to 4 inches, for example), the foreskin itself can be proportionately shorter and end somewhere on the glans, above the end. Thus, to say that the foreskin on these men constitutes 50 to 80 percent of their total penile shaft skin is probably in error, perhaps by a significant amount.

To wrap this up, there are two considerations here: (1) whether or not to use the lining of the foreskin in the calculation, and (2) that more may depend on the function of the foreskin and not its relative size, since relative size can vary so much.

Another way to measure

It is commonly stated that the average size of a foreskin is between 12 and 16 square inches (about the size of a 3” by 5” index card). Even this measurement has been disputed, with some saying that it is half that size. Perhaps, though, the index-card size is a measurement of both the outer skin and inner lining and not the measurement of a folded foreskin, since some experts claim that the total size is considerably smaller – 5.7 to 7.2 square inches, depending on the participants studied.

The size of the penile shaft

As mentioned already, the size of both a foreskin and a penile shaft (the entire penis), varies – somewhat considerably.

Thus, the length of a penis can be a little less than an inch or as long as 2.5 inches. On grown men, an erect penis can be 3 to 4 inches long, or 8 to 9 inches (the size, by the way, of porn stars). The average length on a grown man varies from nation to nation; in the U.S. it is between 5 and 6.5 inches long.

What is worth noting here, is that compared to other primates, including apes and chimpanzees, human penises, are, well, relatively larger. Okay, substantially larger, since a human penis can be 1300 square centimeters compared to 300 to 400 square centimeters – the size of the average ape. Note also, that the human brain is the largest brain of all the primates.

Proportion is relative
and changes during a lifetime.

Note that this statement being discussed – the proportion of penile skin that the foreskin takes up – is about the relative size of the foreskin. Relative to what, though? An infant’s head is 1/4th of his body in contrast to a grown man’s head, which can be 1/6th, 1/7th or even 1/8th of his total height. Likewise, the penis on an infant may change in proportion to his body. In turn, the proportion of the foreskin changes too, and is most dramatic when the penis achieves an erection. During an erection, the penis fills with up to 8 to 10 times as much fluid as usual, however, the foreskin will not experience any growth, just perhaps some stretching.

How much does it grow?

Since we’re on the topic of size, what follows is a related subject, which is the relative size of a flaccid penis compared to an erect penis. Note that during an erection, only the penile shaft, including the glans, but not the foreskin, will fill with fluid and expand. Erection size can depend on a number of factors, including how the male is aroused, the temperature in the room, how often he is aroused, and even the time of day. According to a survey reported in the International Journal of Men’s Health, 79 percent (about 4 out of 5) of males are “growers” and 19 percent (about 1 in 5 males) are “showers”. Here, the distinction is whether a man’s penis gets longer when it fills up with fluid for an erection, or whether it fills up, gets hard, perhaps gets wider, but stays about the length. Slang for a male whose penis grows is a “grower” and slang for a male whose penis stays approximately the same length is “shower.”

Does size matter?

There are numerous studies about sexual satisfaction, and an entire discipline, called sexology. In October 2013, the entire issue of The New York Times Book Review was devoted to reviews of books about sex, many of which, both novels and nonfiction, addressed newer ideas, especially about what women want from their partners. Some of the studies address the difference in satisfaction between circumcised and intact males – both their satisfaction and that of their partner(s).

In conclusion

It is not accurate to make a statement that a foreskin is always half of the skin of a penis. Also, while the relative size of a foreskin may make a difference in the look of a flaccid penis, most erect penises look alike, even very much like erect circumcised penises, especially when viewed from a distance or when the penis is wearing a condom.