About 11.58 cm stretched. Mehraban 2007 measured a random sample of 1,500 Iranian men, which makes it methodologically one of the better studies in this entire register, and it lands 1.82 cm below the figure the map prints.
The claim runs 1.82 cm above the measurement, and the two do not measure the same thing: the claim says erect, the study measured stretched. There is no accepted way to convert between them.
What was actually measured in Iran?
Random sampling is the rare part. Almost every study in this register recruited volunteers, conscripts, or men already attending a urology clinic, and each of those routes bends the sample in a way nobody can fully correct for. Mehraban drew a random sample of 1,500. Whatever else is true of the Iranian figure, it is one of the few that was not assembled from whoever walked through a particular door.
It also measures stretched length, like most of the literature, so it cannot be compared directly with the erect figure the map claims for Iran. The claimed 13.4 cm is 1.82 cm above the study, and the direction of that gap is the same as almost every other country here: the claim is higher than the measurement.
Iran therefore sits in an odd place in this audit. Its study is better designed than most, its claimed figure ignores it as thoroughly as anywhere else, and its position in the ranking, 95th of 119, is determined by a number that the country's own best study contradicts.
How does that compare with the rest of the world?
The claim puts Iran 95th of 119 countries on the ranked list. Here is that number set against the figures that come with a method attached.
Figure
cm
What it is
The claim for Iran
13.40
Labelled erect. No method, no sample size, no reference.
Mehraban et al., Int J Impot Res
11.58
stretched, 1,500 men, 2007. The best located
measurement in Iran.
Clinically measured worldwide
13.12
Erect, 15,521 men. Veale 2015, the pooled clinical figure.
Pooled worldwide
13.93
Erect, 55,761 men. Belladelli 2023, 75 studies.
Pooled for Asia
11.74
Erect, 95 % confidence interval
10.18–13.29 cm
. Belladelli 2023.
That last interval is 3.11 cm wide,
for a whole continent, from the largest meta-analysis there is. The claimed map it sits
under spreads all 119 countries across
7.9 cm and prints every
country to one decimal place. Read those two sentences together and you have the
entire problem with penis size by country.
How many men does the claim cover?
1,500 measured → 32,000,000 described
1,500 men in Iran appear in the studies this register could locate. The claimed figure is applied to roughly 32,000,000 adult men: one measured man for every 21,333.
Where would you land in Iran?
Against the claimed figure, because that is the number people mean when they ask. It
is the weaker of the two numbers above, and the calculator says so. Everything is
computed in your browser and nothing you enter is stored or sent anywhere.
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1,350,250,000men smaller
1,350,240,000men larger
50 of 100 men worldwide are larger than you.
L 13.6 cm
Estimated from the claimed world mean of 13.6 cm across ≈ 2,700,490,000 adult
men in 119 countries. You beat the claimed mean in 31 of them. The
claims are the internet's, not ours; we are grading them one by one.
See the audit.
What should you take from this?
A randomly sampled study of 1,500 men is worth more than a clinic study of 5,000, and it says 11.58 cm stretched. The 13.4 cm on the map is not a refinement of that. It is unrelated to it.
Iran is also a reminder that the quality ceiling in this field is low everywhere. The best-designed sampling in the register still measures the wrong quantity for the question the map claims to answer.
Nearby in the register
The nearest countries with an entry of their own here.
Nearer still, and with nothing to show: Turkmenistan, United Arab Emirates, Azerbaijan. Those
countries carry a claimed figure on every map and no located study behind it, so they
have no page here. The method page lists all of them.
Sources for this page
Mehraban et al., Int J Impot Res, 2007, n = 1,500. Clinician-measured, stretched; random sample.
Study
Veale D et al. Am I normal? BJU International 2015; 115(6): 978–986. The pooled
clinical figures used throughout this site.
Belladelli F et al. Worldwide Temporal Trends in Penile Length. World J Mens Health
2023; 41(4). The regional pooled figures and confidence intervals.
The full reference list, the grading scheme and all 119 claims are on the
method and sources page.