Both men and (to a lesser extent, according to studies) women are curious about the average size of men's genitals. However, studies show that the average penis size is both smaller and more uniform from country to country (and ethnicity to ethnicity) than common pop-cultural assumptions might suggest. Several scientific studies have attempted to determine the worldwide average length of an erect penis. While conclusions have varied, the average length of a human male's penis is generally calculated to be between 12.9 cm (5.1 in) and 13.92 cm (5.5 in). Like average breast size in females, penis size can have an unduly oversized impact on a man's sense of self-worth.
Myths and misconceptions regarding penis size
Although multiple studies have investigated the possible connection between height and penis length, the correlations have proven negligible. Studies have also disproven lingering beliefs that penis size can be detected indirectly by examining the size of one’s hands or shoes—although some studies comparing the lengths of various fingers have claimed a link exists. Either way, studies have determined that males may frequently overstate their penis size when self-reporting, but also consistently underestimate the size of their penis compared to the average size (which they typically assume is larger than it is).
Studies have also determined that women care much less about penis size than men do, and often value girth/circumference as much as or more than length. Women are also satisfied with less than most men might anticipate: A 2015 study found that women shown a selection of 33 3D-modeled penises and given the chance to select the ideal penis size for a long-term partner chose a penis 16.0 cm (6.3 in) in length and 12.2 cm (4.8 in) in girth. In another study, 85% of women stated they were satisfied with their partner's endowment.
Top 10 Countries with the Longest Average Penis Size:
| Country | Erect Length | |
|---|---|---|
| cm | in | |
| Sudan | 17.95 | 7.1 |
| DR Congo | 17.93 | 7.1 |
| Ecuador | 17.59 | 6.9 |
| Republic of the Congo | 17.33 | 6.8 |
| Ghana | 17.31 | 6.8 |
| Nigeria | 17.00 | 6.7 |
| Venezuela | 16.93 | 6.7 |
| Lebanon | 16.82 | 6.6 |
| Colombia | 16.75 | 6.6 |
| Cameroon | 16.65 | 6.6 |
_Source: Little Big Data. Full details for 140+ countries below. _
Top 10 Countries with the Shortest Average Penis Size:
| Country | Erect Length | |
|---|---|---|
| cm | in | |
| Thailand | 9.43 | 3.7 |
| North Korea | 9.60 | 3.8 |
| Cambodia | 9.84 | 3.9 |
| Nepal | 9.98 | 3.9 |
| Myanmar | 10.10 | 4.0 |
| Laos | 10.14 | 4.0 |
| Vietnam | 10.15 | 4.0 |
| Sri Lanka | 10.18 | 4.0 |
| South Korea | 10.80 | 4.3 |
| Philippines | 10.85 | 4.3 |
Factors that influence penis length
Despite common beliefs, race has only a marginal impact upon penis size. A 2014 study of more than 1,600 males determined that the difference in average penis size between white, black, Asian, Native American, and Pacific Islander/Hawaiian men in the US varied by less than an inch. While slight regional trends can be seen when comparing one country's data to another, the differences are generally considered mild overall (particularly given the unreliability of the data set, as explained below).
Although more research is needed, some studies have indicated possible connections between environmental or hormonal factors and penis size. During a person's younger years and adolescence, improper nutrition can impact penile development. Endocrine disruptions, which can be caused by exposure to pesticides, plasticizers, and even natural sources, can negatively impact genital development. Exposure to polychlorinated biphenyls (PCBs), plasticizers, or certain fertility drugs during a mother's pregnancy can decrease penis size in her offspring. Certain radiation therapies can shrink the penises of adult men. Finally, a 2016 study observed that men who were circumcised as newborns tended to have slightly smaller penises.
Why nearly every list of average penis sizes in the world is likely incorrect
Creating a definitive list of average penis sizes across the world's many countries is a daunting task for multiple reasons. The first reason is common to most any cross-country study: Creating a multinational data set typically involves compiling the data from many smaller-scale, regional studies that may or may not have had the same parameters. In the case of penis length, for example, measurement techniques could vary.
The second concern is unique to surveys of a more intimate nature: Most studies of erect penis length rely upon self-reported data, which is notoriously unreliable and easily distorted, rather than more stringent and precise laboratory measurements. Moreover, even if researchers perform the measurements and report them precisely, the possibility of volunteer bias still exists—for instance, given the importance many societies attach to penis size, it is entirely likely that men with larger penises would be more likely to volunteer for a penis size study, which could skewing the sample set unnaturally toward larger penises.
As a result of these concerns, while the data listed below is the most reliable and comprehensive currently available, it should still be taken with a grain of salt.