PhalloMetrics
Penis size data for 142 countries, an estimate by height, and the science of how size develops, plus a plain look at how far the numbers can be trusted.
Estimate by height
How the countries spread out
Number of countries in each length range.
All countries
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How size develops in boys and men
Penis size is set mainly by hormones and genes, in stages from before birth through the teen years.
Hormones shape the tissue
Around weeks 8 to 14 of pregnancy, androgens (testosterone and its stronger form, DHT) turn early genital tissue into a penis. Growth later in pregnancy depends on continued hormone signaling.
Slow and steady
A brief hormone surge in the first months of life is followed by years of very gradual growth. Most of the change comes later, at puberty.
The main growth spurt
Puberty typically starts between about ages 9 and 14, and the first sign is usually larger testicles. Penis growth follows and mostly happens over around two to three years.
Growth levels off
Most boys reach adult size by their mid to late teens, though timing varies a lot. Starting early or late mostly reflects timing and says little by itself about final size.
What drives the differences
Inherited genes matter most, including how sensitive the body’s tissues are to androgens. Hormone levels during development, thyroid and growth hormone, and general health also play a part. Once growth is complete, normal differences in adult testosterone don’t change size.
When to ask a doctor
Worth raising with a pediatrician or endocrinologist: no testicular enlargement by about age 14, genitals that look unusually small or atypical in a baby or child, or a micropenis diagnosis (a rare, statistically defined condition that is often treatable with hormone therapy in childhood).
How environment may factor in
Genes and hormones do most of the work. Researchers study a few environmental influences, but the evidence for effects on adult size is limited.
Chemicals before birth
Some chemicals, including certain phthalates and pesticides, can interfere with androgen signaling. Human studies link prenatal phthalate exposure to shorter anogenital distance in baby boys, and to higher rates of conditions such as hypospadias. Whether this changes adult size is still unsettled.
Nutrition and illness
Severe malnutrition or long-term illness in childhood can slow growth and delay puberty. Growth often catches up once health improves.
Body weight
Fat around the pubic area can bury part of the shaft and make it look shorter. Actual size doesn’t change, but more length can become visible with weight loss. That’s why clinical studies measure from the pubic bone.
Earlier puberty trends
In many countries puberty has been starting earlier on average over recent decades. Suggested causes include nutrition, body fat and chemical exposure. Starting earlier is not the same as ending larger.
Why country comparisons are messy: populations differ in genes and environments, but they also differ in how studies measure and who volunteers. Current data can’t separate those causes.
Facts and myths
Key numbers from Veale et al. (2015), a review of measured data on about 15,500 men.
Measuring properly
Clinical studies measure erect length along the top, with the ruler pressed to the pubic bone. Skipping the bone press gives a smaller reading, and self-reported numbers run larger than measured ones.
Flaccid isn’t a forecast
Flaccid size is a poor predictor of erect size. Stretched flaccid length comes much closer to the erect number.
The normal range is wide
Lengths follow a bell curve with a spread of about 1.7 cm, so around two in three men fall within that distance of the average.
Myth: shoe or hand size
Studies haven’t found a reliable link between penis length and shoe size, hand size, or similar traits. Height has only a weak link.
Myth: pills and pumps work
No pill, cream or device has been shown to reliably increase size, and some cause harm. Surgical options carry real risks and are usually reserved for medical need.
Perception vs. reality
Online media shows a heavily selected group. Many men with typical size worry about it, and persistent distress over normal size can be a form of body dysmorphic disorder that responds well to therapy.
This site offers general education, not medical advice. A doctor can address specific concerns.
States, provinces and local areas
This site doesn’t show state, province or city figures because reliable ones don’t exist. Measured studies are small, drawn from clinics or volunteers, and almost never sampled to represent a region. Maps that rank US states or regions are typically built from search-interest or survey-response data, which says nothing about anatomy.
About the data
- Pooled results from measured studies put the average erect length near 13 to 14 cm (about 5.2 to 5.5 in) and flaccid near 9 cm.
- Self-reported numbers run larger than clinician-measured ones, and some national figures in popular lists are estimates built from other countries’ data.
- Height has only a weak link to length, so knowing it barely narrows the range.
- Variation among individuals within any country is far larger than the gaps between countries.
Country values come from a compilation by Data Pandas (via Visual Capitalist) that combines Veale et al. (2014), Lynn (2013) and other surveys; the Lynn data in particular is widely criticized. The height estimate uses the pooled measured average (13.9 cm), a standard deviation of about 1.7 cm and a weak height correlation (r≈0.2). It is an approximation for curiosity, not a medical tool. For a health concern, a urologist is the right person to ask.