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Average Penis Size

How Research Measures Average Penis Size

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Updated April 04, 2014

Determining the average penis size for a group of males, let alone for men around the world, is more complicated than you might imagine. Unfortunately most information about average penis size comes from popular culture and not science. Let's start by considering some figures from science.

The results from three studies of penis size where the measurements were taken in a laboratory setting give the following ranges:

  • Average penis length (flaccid/not erect): from 3.4 inches to 3.7 inches (8.6 cm to 9.3 cm)
  • Average penis length (erect): from 5.1 inches to 5.7 inches (12.9 cm to 14.5 cm)
  • Average penis girth (circumference when erect): from 3.5 inches to 3.9 inches (8.8 cm to 10 cm)

If you're surprised by these numbers, and can't quite square them with what you read about in popular magazines (or your inbox on a daily basis)and what you see in pornography, there's a reason for your confusion.

First, many statistics you read are not from legitimate research, but from marketing companies who want you to feel bad about your penis size so you’ll buy their product.

Secondly, determining what the average penis size is is more complicated than it seems. It’s a physical body part, you measure it, and repeat hundreds of thousands of times around the world, then take an average. What's the problem? Well arriving at an accurate idea of what is an average penis size, is more complicated. Some of the problems with figuring out average penis size include:

  • Is penis size considered to be the length, the girth, or both?
  • When measuring penis length, where do you start?
  • Is penis girth measured at the base of the penis, at the glans (head), or around the shaft?
  • Are the people measured in these studies representative of the general population?
  • Do all studies include measurements taken by others, or self-reported measurements (which are historically bigger than measurements reported by others)?

Different studies answer these questions differently, which makes arriving at a single average penis size almost impossible. Also, many researchers believe that those who are willing to participate in a study about penis size may have larger than average penises, which would skew the results.

Sources:

Awwad, Z., Abu-Hijleh, M., Basri, S., et al. "Penile Measurements in Normal Adult Jordanians and in Patients with Erectile Dysfunction" International Journal of Impotence Research Vol. 17, No. 2 (2005): 191-195.

Bondil, P., Costa, P., Daures,J.P., et al. "Clinical Study of the Longitudinal Deformation of the Flaccid Penis and of its Variations with Aging" European Urology Vol. 21, No. 4 (1992): 284–286.

Hocking, J., Smith, A.M., Benton, K., et al. "Does Penis Size Influence Condom Slippage and Breakage?" International Journal of STD & AIDS Vol. 9, No. 8 (1998): 444–447.

Kinsey, A., Pomeroy, W. & Martin, C. Sexual Behavior in the Human Male. Philadelphia, WB Saunders, 1948.

Richters, J., Gerofi,J., & Donovan, B.. "Are Condoms the Right Size(s): A Method for Self Measurement of the Erect Penis" Venereology Vol. 8, No. 2 (1995): 77–81.

Schneider, T., Sperling, H., Lummen, G. et al. "Does Penile Size in Younger Men Cause Problems in Condom Use? A Prospective Measurement of Penile Dimensions in 111 Young and 32 Older Men" Urology Vol. 57, No. 2 (2001): 314-318.

Wessells, H., Lue, T.F. & McAninch, J.W. "Penile Length in the Flaccid and Erect States: Guidelines for Penile Augmentation" The Journal of Urology Vol. 156, Issue 3. (1996): 995-997.

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