Studies and Research To Determine Average Penis Size

The question of penis size and possibly more specifically, what is considered to be average intrigues most men at some point or other in their lives. Whilst sexologists continually emphasize that penis size ranks fairly low on most women's lists of physical attributes, men nevertheless generally consider the size of their penis to be a fundamental measure of masculinity and ability to sexually satisfy a partner. Indeed, there is no doubt penile size can have a significant impact upon levels of self-esteem and confidence. The belief of 'not measuring up' or having a smaller than 'average' penis can result in feelings of both inadequacy and anxiety.

Many scientific studies have attempted to determine average penis size. Interestingly, although conclusions have not differed substantially, results have tended to vary to some degree.
Often, the results of surveys have been based on data gathered from men who measured themselves. In these cases, inaccuracies have often arisen due to incorrect self-measurement or a tendency to exaggerate penis size. Studies that have used medical staff to accurately measure erect penis size have often suffered because conclusions have been based on measurements taken from a small sample of men. 

Although the above difficulties do exist, it is still possible however, to gain a fairly accurate idea of what is considered 'average'.

One of the most famous and exhaustive studies conducted into penis size was performed by Alfred C. Kinsey and his associates in 1948 using data collected from 3500 college males. Recent analysis of the Kinsey data has concluded that mean erect length measured 6.21 inches with a standard deviation of 0.77 inches whilst mean erect circumference measured 4.85 inches with a 0.71 inch standard deviation.
According to the same survey and analysis, mean flaccid length measured 3.89 inches with a 0.73 inch standard deviation whilst flaccid circumference measured a mean of 3.75 inches with a standard deviation of 0.65 inches. Erect penile length measurements were taken along the top of the penis from the pubic area to the tip whilst circumference measurements were taken from around the middle of the penis.
Whilst the Kinsey data provides invaluable insight into average penile length and girth, it should be noted that results were based on data gathered from men who measured themselves. Volunteers simply held postcards against their penises, marked length against the card and posted the results. It is therefore debatable as to how accurate many of these measurements were. Furthermore, only white Caucasian males were included in the survey and as such the results were not representative of a diversity of races.

Several condom manufacturers have conducted more recent research into penis size in an attempt to provide better fitting products. Of particular interest are the surveys conducted by Durex and Lifestyles Condoms.

Durex' recent Internet based survey gathered data from 2,936 men from 27 different countries across all five continents. The bulk of respondents (39%) were in the United States, whilst 9% lived in the UK, 7% in Canada and 4% in the Netherlands. Unfortunately, again the overwhelming majority of respondents were white and it was therefore impossible to break down data by ethnic origin.
The Durex survey concluded that out of all those who responded, average erect penile length measured 6.4 inches with a standard deviation of 1.1 inches whilst average erect circumference measured 5.2 inches at the widest point of the penis with a standard deviation of 0.8 inches.
Although the research sample of men was sizeable, again the accuracy of the raw data could not be verified. As with the Kinsey report, results were based on data gathered through self-measurement. Furthermore, the entire study was conducted anonymously via the Internet.

In an attempt to obtain far more accurate and 'unbiased' measurement data, Lifestyles Condoms recently conducted their own survey during Spring 2001 in Cancun, Mexico using a far more strict measurement methodology. 
A total of 301 subjects, over the age of 18 were measured, one at a time, by qualified medical staff. Most of the sample consisted of U.S. College students although participation was not limited to this group. To ensure accuracy, measurements of erect size were taken by two out of a team of four nurses supervised at all times by a doctor. As with the above studies, erect penile length was measured along the top of the penis from the pubic area to the tip of the glans whilst erect circumference measurements were taken from around the middle of the penile shaft.

The results of the Lifestyles study indicated that average penis size was less than previously assumed and determined that erect length averaged 5.877 inches with a standard deviation of 0.825 inches whilst erect girth averaged 4.972 inches with a standard deviation of 0.508 inches. Furthermore, according to the survey, 54% of subjects measured between 5.5 inches and 6.3 inches in erect length with 53.33% measuring between 4.725 inches and 5.118 inches in circumference.

It would appear that subjects do indeed exaggerate measurements when permitted to measure themselves and this therefore, throws into doubt the results of any survey based on self-measurement data. Other studies into penile size that used strict measurement methods have also suggested that average erect penis length is less than the 6.2 - 6.4 inches often concluded by studies relying on self-measurement procedures.

Similar results to those achieved by the Lifestyles study were recently reported by a Brazilian urologist who accurately measured 150 subjects and determined average erect length to be 5.7 inches and average circumference to be 4.7 inches.

In conclusion, considering all the above data, it would seem fair to suggest that the 'average' erect penis measures between 5.5 and 6.5 inches in length and between 4.5 and 5.5 inches in circumference. It would appear that well over 50% of men in any given population fall within these figures. Whilst a wide diversity of sizes will occur in any given sample, the percentage of men reporting a certain size diminishes rapidly the further away from the above averages one gets. Taking an example from the Kinsey data to illustrate, whilst 17% of the 3500 men studied reported an erect length or 7 inches or above, out of these 17% of men only 1.8% reported an erect length of 8 inches or over.