Penis Size By Country

The difference in average erect penis length between the highest-ranked country and the lowest is 8.16 centimeters, roughly the width of a smartphone. Ecuador leads the dataset at 17.59 cm, while Thailand sits at the opposite end at 9.43 cm. In between, 140 other countries span a range that is wider than most people assume.

The global average across all 142 countries in the dataset is approximately 13.44 cm (5.3 inches), a figure that aligns closely with the 2015 BJU International systematic review of over 15,000 clinician-measured men, which found an average of 13.12 cm. But averages obscure the real story: the data clusters sharply by geography, and the rankings shift dramatically depending on whether you measure length, girth, or volume.

One important caveat before diving into the numbers: roughly a third of the studies in this dataset rely on self-reported measurements, which consistently run larger than clinician-measured ones. Research published in the Journal of Urology found that men overestimate their own length by an average of nearly a centimeter. Where possible, the data has been adjusted to account for this bias, but it remains the single biggest source of noise in any cross-country comparison.

The top of the rankings draws a line across the tropics. Every country in the top 10 for erect length sits between the Tropic of Cancer and the Tropic of Capricorn. Ecuador, Republic of the Congo, and Nigeria hold the top three spots, followed by Venezuela, Colombia, Sudan, and DR Congo. Jamaica, Ghana, and Senegal complete the top 10. No country above 35° latitude appears in this tier.

Ecuador's average of 17.59 cm stands more than 4 centimeters above the global mean, a gap wider than any other country in the dataset. The measurement comes from a 2013 University of Guayaquil study of 1,000 men, one of the larger sample sizes in the dataset. Behind Ecuador, the Republic of the Congo (17.33 cm, N=157) and Nigeria (17 cm, N=18) round out the top three, though Nigeria's tiny sample makes its placement less certain.

Latin America and Sub-Saharan Africa account for 18 of the top 20 countries by length. The pattern is not random. Researchers have pointed to a combination of genetic factors, hormonal profiles, and developmental conditions that may vary by population and latitude. But no single cause fully explains the clustering. What the data does show clearly is that the gap between the tropical top and the global middle is substantial: the top five countries average 17.12 cm, nearly 4 cm above the global mean.

Surprisingly, most searches about penis size by country are not about who ranks biggest. They are about who ranks smallest. The answer forms one of the clearest geographic patterns in the entire dataset: Southeast Asia dominates the lowest rankings.

Thailand (9.43 cm), North Korea (9.6 cm), and Cambodia (9.84 cm) anchor the very bottom of the rankings. Just above them, Nepal (9.98 cm), Myanmar (10.1 cm), Laos (10.14 cm), and Vietnam (10.15 cm) all fall below 10.2 cm.

Sri Lanka (10.18 cm), Indonesia (10.37 cm), and South Korea (10.8 cm) sit just above that cluster. In total, 10 of the bottom 12 countries are East or Southeast Asian.

The gap between these countries and the global average is roughly 3 to 4 centimeters, nearly the same magnitude as the gap at the top. Why? Researchers cite a combination of factors. Genetics play a role: penis size is a heritable trait influenced by multiple genes, and population-level genetic differences are real, if modest. Nutrition and childhood health also matter. Studies have suggested that nutritional deficiencies during early development can impact growth. Many of the countries at the bottom of this ranking were, during the study periods, lower-income nations where childhood malnutrition was more prevalent.

There is also a measurement factor. Thailand's data comes from a 1,800-person study at Mahidol University's Siriraj Hospital, one of the most rigorous in the dataset. South Korea's comes from a 878-person Journal of Urology study. These are clinician-measured, controlled studies. Some countries higher in the rankings relied on self-reported surveys, which tend to inflate results. The bottom of this list may partly reflect better data, not just smaller averages.

If you only look at length, you miss a major dimension. Erect girth (circumference) shows almost no relationship with erect length across the 141 countries where both metrics are available. A country can rank in the top 10 for length and land in the middle of the pack for girth, or vice versa.

The most dramatic example is France. It ranks just 32nd in erect length at 14.5 cm, barely above the global average. But France leads the entire dataset in erect girth at 13.63 cm, more than a full centimeter above the next-closest country (Netherlands at 13.55 cm). The measurement comes from a 3,260-person study at the Paris National Academy of Surgery, one of the largest and most rigorous in the dataset.

This disconnect matters because volume, the three-dimensional measure of overall size, depends on girth squared. When you calculate volume (π × radius² × length), differences in girth get amplified far more than differences in length. The result is a dramatic reshuffling of the rankings.

The Netherlands jumps from 17th in length to 3rd in volume (227.93 cc). France leaps from 32nd in length to 6th in volume (214.36 cc). Meanwhile, Nigeria, which ranks 3rd in length, drops to 16th in volume because its girth (12.35 cm) is closer to average. The countries that top the volume rankings, led by Ecuador (252.85 cc), Venezuela (228.74 cc), and the Netherlands, are the ones that score well on both dimensions, not just one.