Penis size: what science says (and why you can relax)

1. Average size in France and worldwide: the real figures

The figures you often see online are frequently overestimated because they rely on self-reporting (spoiler: pride can lead men to add a few millimetres, or even centimetres).

When healthcare professionals use a strict measurement protocol, the scientific picture looks very different.

In France: flaccid and erect

A key international reference is the study by Dr Veale and his team, published in the prestigious urology journal British Journal of Urology International (BJUI) (based on a sample of more than 15,000 men worldwide). Combining those findings with reports from France’s National Academy of Surgery gives us:

• Average flaccid length: around 9.16 cm.
• Average erect length: around 13.12 cm.
• Average circumference: around 9.31 cm when flaccid and 11.66 cm when erect.

💡 Did you know? Size when flaccid doesn’t tell you how big a penis will be when erect! Medicine and sexology distinguish between showers (larger when flaccid but changing little during an erection) and growers (smaller when flaccid but growing considerably as blood flows in during arousal).

By country: are there real geographical differences?

You hear all sorts of conflicting claims about supposedly huge differences between continents. The scientific reality is much more nuanced:

• Average statistical differences between countries rarely exceed 1 to 1.5 cm.
• Most of the interactive maps and viral rankings online rely on unverified or self-reported data.
• Comparative biometric studies show that individual variation within a single country is far greater than the small differences in averages observed between countries.

Has size changed over time?

A meta-analysis published in the World Journal of Men's Health examined changes in penis size over the past 30 years. It found a slight increase in average erect length worldwide.

Scientists have proposed several possible explanations: environmental changes, exposure to endocrine disruptors and changes in diet. However, researchers remain cautious and point out that measurement methods have also changed.

2. How do you measure a penis properly?

If you’ve ever tried to measure your penis with a plastic school ruler at 2am, you should know that medicine follows a strict method to avoid bias:

1. Position: measure along the upper side (the top of the penis), from the pubic bone to the tip of the glans.
2. Compressing the pubic fat pad: press the ruler firmly against the pubic bone (the layer of fat beneath the skin of the lower abdomen can conceal 1 to 3 cm of the shaft!).
3. Circumference: measure it with a flexible tape measure, usually around the middle or base of the shaft.

3. Bell curves, what’s "normal" and micropenis: what do these terms mean?

Statistically, penis size follows a bell curve (or Gaussian curve).

• The typical range: around 95% of men have a penis measuring between 10 cm and 16 cm when erect. If you fall outside that 95%, it doesn’t mean you’re not “normal” — just that you’re outside that range.
• Micropenis (medical definition): medically, a micropenis is a penis whose length is more than 2.5 standard deviations below the average. When erect, this means a penis measuring less than 7 to 7.5 cm. It’s a rare medical condition (affecting around 0.6% of the population), often linked to a hormonal deficiency during foetal development.

4. At what age does the penis reach its final size?

Penis growth is directly linked to puberty and surges in testosterone:

• It generally begins at around 11–13 years of age
• Most development takes place over 4 to 5 years
• On average, the penis reaches its final size and shape between 18 and 21 years of age

After that age, anatomical size no longer changes naturally. Be wary of miracle creams or exercises sold on dubious websites: they don’t work. At best, they’re ineffective; at worst, they’re dangerous!

5. Physical traits and penis size: myths or facts?

Foot, hand and nose size, body hair, overall height: do your size 46 shoes really reveal anything about your anatomy?

• Shoe size / hand size: MYTH. Studies have found no significant correlation between shoe size and penis length.
• Overall height: a very weak correlation. A man who’s 1.90 m tall doesn’t necessarily have a bigger penis than a man who’s 1.65 m tall.
• The index finger vs the ring finger (known as the Manning index, or 2D:4D ratio): a South Korean study published in the Asian Journal of Andrology suggests a very slight correlation between the difference in length of these fingers and penis size (linked to testosterone exposure in the womb). But it tells you very little about any one person.

In short: no visible physical feature can predict penis size.

6. Does size really matter?

a) Anatomical compatibility matters more than size

Rather than talking about size alone, sexologists talk about anatomical fit or how well bodies fit together. A vagina isn’t a rigid tube: it’s an elastic, expandable muscular cavity, typically 7 to 10 cm deep at rest, that lengthens during arousal.

A penis considered "too big" may be uncomfortable or even painful for some vaginas, while a shorter or wider penis may suit others perfectly. It’s how the shape, flexibility and comfort of both bodies come together that makes a good fit — not a single measurement on a ruler!

💡 Bonus: intimate accessories Because every body and every anatomy is unique, there are simple ways to adjust sensations and comfort during penetration:

• Penetration depth limiters: if a penis feels too long or deep thrusting is painful or uncomfortable, these soft silicone cushioning rings fit at the base of the shaft. They act as a comfortable "buffer", limiting penetration depth without reducing the intensity of the rhythm or movement.
• Penis sleeves that add girth: conversely, if a couple wants to explore a fuller sensation or bridge a difference in fit, a penis sleeve fits over the shaft to add a few millimetres of girth and/or length, while its texture provides stimulation for both partners.

b) An essential reminder: sex is about far more than penetration 

It’s probably the most persistent misconception inherited from patriarchal culture and mainstream porn: the idea that sex is nothing more than moving a penis in and out. That’s completely wrong and reductive!

• What counts as sex? Touching, oral stimulation, mutual masturbation, anal play, kissing, intimate massage (and many other activities) are all sexual acts in their own right. Sex is absolutely not defined by whether penetration takes place!
• Female anatomy: the clitoris is the ultimate pleasure organ, with 8,000 to 10,000 nerve endings spread across its external glans and the internal structures surrounding the vaginal opening. The deeper two-thirds of the vagina, meanwhile, have relatively few nerve endings: its most sensitive area is the first 3 to 5 centimetres from the opening, where friction can stimulate the internal bulbs of the clitoris!
• What the studies say: according to a UCLA study on body image, 84% of women say they’re completely satisfied with their partner’s penis size (while 45% of men think theirs is too small). In our Kantar / Passage du Désir studies on sexuality in France, it’s closeness, listening, consent and variety that make pleasure take off in bed — long before body measurements come into it.

7. Condoms and sex toys: how do you choose the right size?

If there’s one area where size really matters, it’s safety and comfort. 

The truth about condoms sold in pharmacies

If you’ve ever felt squeezed or compressed — or, on the contrary, as though you were "swimming" — in a standard condom bought over the counter, you’re not alone.

In pharmacies and supermarkets, the choice is extremely limited. Almost every box comes in a standard size (52 to 54 mm nominal width). And the supposed "large sizes" sold in pharmacies (labelled XL or King Size) aren’t really that large: they rarely exceed 56 mm in width. For slimmer penises (< 50 mm) or larger circumferences (60 mm to 69 mm), a typical pharmacy simply doesn’t cater to the need.

However, nominal width (related to circumference) is the key factor: a condom that’s too tight may restrict blood flow, cause an erection to subside or tear, while one that’s too loose may slip off.

🛍️ Our (well-researched) advice: there’s a much wider choice online than in pharmacies. As long as you choose a trustworthy site, you can find condoms sized down to the millimetre (such as the My.Size range). And if you’d rather not face someone at the till, don’t worry: sites like passagedudesir.com deliver in completely plain, discreet packaging, with no mention of the retailer on the box.

Choosing your sex toys and accessories

• Penis rings (cock rings): if you’re trying cock rings to help maintain an erection or intensify sensations, choose soft, stretchy silicone models.
• Penis masturbators : most sleeves and masturbators (such as the well-known silicone eggs and sleeves) are highly stretchy and fit a wide range of shapes and sizes.
• Some lubes: if a toy feels tight, add a little water-based lube and you’ll almost certainly find it more pleasurable and comfortable.

So what’s the takeaway?

Penis size should never be an obsession or a source of anxiety or insecurity. Sex is a playground where creativity, listening, touch, lubes and closeness matter a thousand times more than a few centimetres on a ruler.

Take care of yourself and have fun! ❤️

📚 Scientific sources & references

• Veale D. et al. (2015) - Am I normal? A systematic review and construction of nomograms for flaccid and erect penile length and circumference in up to 15 521 men - BJU International
• National Academy of Surgery (France) - Opinion on surgery to increase penile girth and length
• Eisenberg M.L. et al. (2023) - Worldwide Temporal Trends in Penile Length: A Systematic Review and Meta-Analysis - World Journal of Men's Health
• Lever A.G. et al. (2006) - Does Size Matter? Men's and Women's Views on Penis Size Across the Lifespan - UCLA / Psychology of Men & Masculinity

Related blog posts: