Penis Size By Country

The data behind this ranking draws from dozens of studies conducted across 142 countries over several decades. Some were clinician-measured in hospital settings. Others relied on self-reported surveys, which consistently produce inflated numbers: peer-reviewed urology research has found that men overestimate by roughly a centimeter on average. To correct for that, all self-reported values in this dataset were adjusted downward by 1.3 cm for length and 1.1 cm for girth before publication.

After that correction, the range is still wider than most people expect. The gap between the top and bottom countries is 8.16 centimeters, roughly the width of a smartphone. Ecuador leads at 17.59 cm. Thailand sits at the opposite end at 9.43 cm. The global average across all 142 countries lands at approximately 13.44 cm (5.3 inches), a figure that aligns closely with the 2015 BJU International review of over 15,000 clinician-measured men.

The rankings also shift dramatically depending on whether you measure length, girth, or volume. Those three dimensions tell very different stories.

The top of the ranking 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. Venezuela, Colombia, Sudan, DR Congo, Jamaica, Ghana, and Senegal fill out the rest. No country above 35° latitude cracks the top 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 University of Guayaquil study of 1,000 men, one of the larger clinician-measured samples available.

Behind Ecuador, the Republic of the Congo (17.33 cm) and Nigeria (17 cm) round out the top three. Nigeria's sample is just 18 men, however, which makes its placement less certain.

Latin America and Sub-Saharan Africa account for 18 of the top 20 countries by length. 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. 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.

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. 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. Genetics play a role: penis size is a heritable trait influenced by multiple genes, and population-level differences are real, if modest.

Research has also linked nutritional deficiencies during early development to reduced growth across multiple physical measures. Many of the countries at the bottom of this ranking were, during the study periods, lower-income nations where childhood malnutrition was more prevalent. None of the bottom-ranked countries relied on self-reported data: Thailand's measurement comes from a 1,800-person study at Mahidol University's Siriraj Hospital, and South Korea's from an 878-person study published in the Journal of Urology. These are controlled, clinician-measured studies.

If you only look at length, you miss a major dimension. Erect girth (circumference) shows almost no relationship with erect length across the 142 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, edging out 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.

The measurements in this ranking were not collected by a single research team using standardized methods across all 142 countries. They come from a compilation published by Richard Lynn at the University of Ulster in 2013, which aggregated data from dozens of individual studies conducted over several decades. Some of those studies were clinician-measured under controlled conditions. Others relied on volunteers self-reporting their own measurements.

To account for the well-documented tendency of men to overestimate, all self-reported values in the dataset were adjusted downward: −1.3 cm for length and −1.1 cm for girth. Those correction factors align with peer-reviewed urology research showing that roughly 73% of men report a number higher than what clinical measurement produces. The adjustment narrows the gap between self-reported and measured studies, but it cannot eliminate every methodological difference.

Even after the correction, comparing studies directly remains difficult. Venezuela leads in sample size with 4,610 men measured by researchers at the University of Venezuela. France contributes 3,260 clinician-measured men. Nigeria, by contrast, ranks 3rd in the world with data from just 18 men. Comparing a South American military survey of thousands to a study of 18 from a single source is a stretch, regardless of how the data was collected.

Academic criticism of the underlying dataset has been direct. Jelte Wicherts, a professor of methodology at Tilburg University, stated that portions of Lynn's compilation relied on unverified sources and that "the data has no methodology."

For a more reliable baseline, the 2015 BJU International review by David Veale and colleagues at King's College London remains the gold standard. It analyzed 17 studies covering 15,521 men measured by health professionals using standardized techniques. Its finding: a mean erect length of 13.12 cm and a mean erect circumference of 11.66 cm. The patterns in this country-level dataset are still real: tropical countries do report larger averages and East Asian countries report smaller ones, even after the self-report correction. But the precise rankings should be read as approximate, not definitive.