Size by country: the map that lies

The viral world maps of penis size trace back to one unreviewed web compilation. Where they come from, why the rankings mean nothing and what clinic-measured data really show

You have seen the map. A world painted in shades from pale to dark, each country with a number in centimetres, shared with a wink and a flag emoji. It looks like geography. It is mostly a game of telephone, played with data that were never meant to be compared, and it usually ends up saying more about the people who made it than about the men who live there.

Where the maps come from

Follow almost any viral ranking back far enough and you arrive at a 2013 paper by the psychologist Richard Lynn, published in Personality and Individual Differences. Its goal was not cartography: it was written to test J. Philippe Rushton's theory of race differences, which tried to link penis size, intelligence and race, and it sorted the world's countries into old racial categories to do so.

The numbers for 113 countries did not come from new measurements. Lynn took them from a website, retrieved in 2011, that had compiled figures "from research centres and reports worldwide". By his own description, the composite data on that site were unpublished and not peer-reviewed, and in some countries the erect length was self-reported while in others it was measured by someone else. Those two kinds of number ended up side by side in the same table.

Ranking sites then took the baton. DataPandas, one of the most visible, says its figures come from Lynn's compilation, with self-reported values corrected downward by a fixed amount, and admits that sample sizes range from 18 men to 4,610 men. A blanket correction cannot fix a dataset in which each country was measured differently. It just makes the error look tidier.

Why the rankings fall apart

Even if every number were honest, a ranking only works when everyone is measured the same way. Here, almost nothing is the same:

• Self-report against clinic. Men who measure themselves report more. Asked privately, 130 college men gave an average erect length of 16.8 cm6.6 in, far above the clinic figure, and the men who care most about looking good reported the most (more in Why everyone adds an inch).
• Soft, stretched or hard. In clinician-measured data the average flaccid length is about 9.2 cm3.6 in, stretched about 13.2 cm5.2 in and erect about 13.1 cm5.2 in. Put a flaccid study from one country next to an erect one from another and you have a difference of several centimetres that is pure method.
• Who gets measured. Many clinical studies measure the men who happen to be in front of a urologist. In the 2023 meta-analysis, 36 of the 75 studies used urology patients and 14 measured men before prostate surgery, against 23 with volunteers. Volunteers, in turn, may be the men most comfortable with their size.
• How the erection is produced. An injection in the clinic, a spontaneous erection, or a stretched measurement that tries to imitate one: the same review counted all three methods among its studies.
• Tiny samples. A national figure based on a few dozen men can move by more than a centimetre just by chance, and a ranker cannot tell that apart from a real difference.

What careful studies show

Clinician-measured meta-analyses, which throw out self-reports, do find differences between regional averages. Belladelli and colleagues pooled 75 studies with 55,761 men and reported erect lengths from about 11.7 cm4.6 in in Asian studies to about 15.7 cm6.2 in in Oceania, with Europe, the Americas and Africa in between. A 2025 analysis by WHO region, using 33 studies with 36,883 men, found the largest stretched and flaccid averages in the Americas.

Now read the fine print. The erect averages in the 2023 review rest on just 20 studies in total, and the Oceania figure on a single study. The confidence intervals are wide: Africa's erect average could lie anywhere between 12.5 cm4.9 in and 17.3 cm6.8 in, Europe's between 12.5 cm4.9 in and 15.7 cm6.2 in, Asia's between 10.2 cm4 in and 13.3 cm5.2 in. Those ranges overlap so much that the order of the regions is anything but settled. The authors themselves note that most studies did not give enough detail for a finer geographic breakdown.

The most instructive result comes from a 2025 meta-analysis of Chinese men. Compared with a global reference, they were shorter when soft, at 7.4 cm2.9 in against 9.1 cm3.6 in, but there was no significant difference in erect length or erect girth: they simply grew more on erection, about 67% against 43%. A map built on flaccid numbers would have put them near the bottom. Measured hard, the gap disappears.

The difference that actually matters

Suppose the regional gaps were real and exact. They would still be small next to the spread among men from the same place. Using the clinic figures, the shortest 5% of men are below about 10.4 cm4.1 in erect and the longest 5% above about 15.9 cm6.3 in: a range of about 5.5 cm2.2 in inside the middle 90% of any population. The difference between most regional averages is a fraction of that.

In practice, that means a country, a skin colour or a passport tells you almost nothing about the man in front of you. Two men from the same street can differ by more than two continents' averages. This is also why "region" is a poor stand-in for anything biological: it bundles together diet, height, body fat, how studies recruit and who agrees to drop his trousers for science.

So, about the map

This is the map that keeps going round, rebuilt from the numbers of one of the ranking sites that publish it. Every country gets a precise figure, most of them to two decimals.

The honest version would have most countries in grey for "no reliable data", a handful coloured from a few hospital studies, and a large caption saying the differences between them are smaller than the differences within them. Nobody would share it, which is the point. So here it is, built only from studies where a health professional held the ruler.

Country by country, the two side by side. The online figure is a claimed erect length, the measured one a stretched length, so they are not the same thing: the point is how many of the online numbers have nothing at all behind them.

118 of the 135 countries on the online map have no stretched-length measurement by a doctor at all

If you want to know where you or a partner stand, compare with the clinic-measured averages in Length and the methods in How to measure. The rest of what does and does not predict size is in What predicts size. And the next time the map appears in your group chat, you can be the man who asks where the numbers come from.