ICRA logo


The typical limp adult human penis is about 3 centimeters in diameter at the base and somewhere between 8.5 and 10.5 cm long (measured along the top)—but fathers have been shorter than 3 cm, and lengths as great as 30 cm are reported. In general, smaller penises lengthen proportionally more than large ones do during an erection, but though the difference between small and large is reduced, the larger remain larger. The erect penis is about 15 to 19 cm long  with, again, many functioning very well outside this range.

Some psychologists believe that the ready availability in recent years of pornography featuring male actors at the far edge of the penile size range has given many men a troubling but distorted conception of what constitutes “normal” penile size.

As penises go, humans’ are not wonders of the animal world. In many mammals—the raccoon, for example—the penis is stiffened with a bone, something men must pay a surgeon to achieve, and in plastic at that. In size humans are dwarfed: the bull’s is 3 feet, the elephant’s 5 feet, the blue whale’s 7 to 8 feet, and even a small animal like a pig, domestic or wild, has 18 inches. However, humans do have the longest flaccid penis of any primate.

Penile size and female preference

Counselors, marriage handbooks, and sensitive women assure us that there is no correlation between penile size and lovemaking ability. Xaviera Hollander, an author who claims professional expertise of a practical sort, agrees about the lovemaking but says size does matter, and comments: “Men worry mainly about length, whereas women care more for girth.… If he’s all the way in, up against her cervix, yet there are still two inches on the outside, those are two useless inches. Girth is another matter.… A penis is hardly ever too thick.”1

In a 2013 study,2 women were shown projected, life-size, digitally-generated images of a full frontal nude man and asked to rate their sexual attractiveness.

1. Xaviera Hollander.
Xaviera's SuperSex.
New American Library, 1976.

Page 134.

2. Brian S. Mautz, Bob B. M. Wong, Richard A. Peters, and Michael D. Jennions.
Penis size interacts with body shape and height to influence male attractiveness.
PNAS April 8, 2013
Published online before print April 8, 2013,
doi: 10.1073/pnas.1219361110

Penile size and size of other body parts

One of the most curious facts about the human penis is that, of all the organs of the male body, e.g., heart, lungs, brain, liver, and so on, the size of the penis is least related to skeletal size.1

An old myth holds that penis size is correlated to shoe size; the bigger the shoe, the longer the penis. A scientific study has shown that this is not true.2

For many years, a relationship between the reait has been suspected is correlated with penile length. The mechanism suggested for such a correlation is the effect of hormones in the womb.

1. G. A. Piersol.
Human Anatomy.
Philadelphia: Lippincott, 1907.

Confirmed by Masters and Johnson, Human Sexual Response, 1966, page 192.

Robert Latou Dickinson.
Human Sex Anatomy.
Baltimore: Williams and Wilkins, 1933.

P. Bondil, P. Costa, J. P. Daures, J. F. Louis, H. Navratil.
Clinical study of the longitudinal deformation of the flaccid penis and its variations with aging.
European Urology, vol. 21 no. 4, pages 284-286 (1992).

2. Jyoti Shah and N. Christopher.
Can shoe size predict penile length?
BJU International. vol 90, pages 586-587. (2002)

There are earlier studies but they are flawed. Despite Richard Edwards' conscientious efforts, the data on which his ongoing internet survey is based are largely self-reported, and therefore unreliable. He found the correlation between shoe size and penis length to be insignificant. See www.sizesurvey.com/result.html . Another study found a weak correlation:

K. Siminoski and J. Bain.
The relationships among height, penile length, and foot size.
Annals of Sex Research, vol. 6, pages 231-235 (1993).


for further reading

Mels van Driel.
Paul Vincent, translator.
Manhood. The Rise and Fall of the Penis.
London: Reaktion Books, 2009.

An authoritative entertainment for laymen written by a Dutch urologist.

David M. Friedman.
A Mind of Its Own: A Cultural History of the Penis.
Free Press, 2001.

A compendium on attitudes over the ages.

J. L. McCary.
Sexual Myths and Fallacies.
New York: Van Nostrand Reinhold Co., 1971.

home | people index | search |  to email Sizes drawing of envelope |  acknowledgements | 
help | privacy | terms of use