How Big Is The Average Penis – And Why Do Men Even Care?

Good news fellas: you're almost certainly completely normal.


Dr. Katie Spalding


Dr. Katie Spalding

Freelance Writer

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory.

Freelance Writer

Six bananas next to a measuring tape

It's not about the size, it's about what you do with it. Uh - a banana, that is. Image credit: 3623/

Dicks! Big ones, small ones, absolutely colossal ones – it seems humanity just can’t get enough of these funny little dangly bits. As a species, we’re obsessed: why isn’t it hard? Why isn’t it floppy? Oh god, is it even summer ready?

But for some people, it’s more than just a fascination. It’s a problem. Men the world over fear their most private of parts are simply not good enough – or, to be more accurate, not big enough. 


And yet, at the same time, we know that penises are bigger than ever – and as any urologist will tell you, dude, you’re almost certainly normal-sized. So why are so many people hung up on this one piece of anatomy? How big is big enough? And what actually is “normal”, anyway?

Why are men so hung up on penis size?

This may not come as a surprise, but a lot of men – and, to a lesser extent, other people too – really care about penis size. 

“It is very common for men to worry about the size of their penis,” noted Kevan Wylie, specialist in sexual health and erectile dysfunction and author of a six-decade strong review into attitudes towards penis size published in 2008. “It is important that these concerns aren't dismissed as this can heighten concerns and anxieties.”

And when we say common, we mean it: the size of the prize comes up in the top three most-worried-about aspects of men’s bodies, with studies finding that around two out of three of men are not satisfied with their personal largess. It’s such a widespread problem, in fact, that it even has its own name in the literature: “small penis syndrome” – referring not, as it may sound, to an undersized member, but to a normal one attached to somebody convinced otherwise.


Part of that is undoubtedly due to media exposure – although not as much as you might think. “Although effect sizes were small, […] exposure [to sexually explicit material] negatively affected the overall body satisfaction and genital state self-esteem of our male participants,” concluded one 2019 study into the causes of genital anxiety in men. 

“We are not yet fully cognizant of the effect – if any – that easy accessibility to SEM [sexually explicit material] has on the body expectations and body ideals of consumers,” the authors add, although they note that their results “also suggest […] the influence of SEM on state self-esteem is perhaps less ubiquitous than SEM opponents claim – with no similar significant effect found among women.”

But if not porn, what is causing this widespread anxiety over penis size? One intriguing possibility, put forward in a study from 2019, suggests it may come from how men think about their dicks in relation to themselves.

“Mean (±SD [standard deviation]) self-reported penis length […] among sexually experienced men was 6.62 ± 1.11 inches,” the authors point out – while “mean (± SD) penis size reported by sexually inexperienced men (5.67 ± 0.85 inches) was significantly smaller.”


“We speculate that the difference between the two groups is due to a greater sense of masculinity and sexual competence and prowess by experienced men,” they suggest. In other words: the more macho you consider yourself, the larger you may think your penis ought to be. 

“The whole issue is how much men actually look at their penis size as a stand-in or surrogate for their degree of masculinity,” agreed Abraham Morgentaler, a urologist at Men’s Health Boston who treats issues of male sexuality, back in 2015. “And we can argue that it shouldn't – that we should be more highly evolved than that – but whatever we may think, we're left with what guys actually do, and they are concerned about it.”

So what actually is the average penis size?

There are some four billion penises on this planet, and so to find a true indication of the average length between them all would be, let’s face it, a mammoth undertaking.

Luckily for us, somebody out there had the gumption to do it. In 2014, a review dropped that took data from more than 15,000 men across the world – measured by a health professional using a standard procedure, rather than using self-reporting – to calculate the dimensions of the average penis.


So what were the results? You may be surprised: “The average length of a flaccid penis was 9.16 cm [3.6 inches], the average length of a flaccid stretched penis was 13.24 cm [5.21 inches], and the average length of an erect penis was 13.12 cm [5.165 inches],” the authors concluded in a statement

Nomogram for flaccid, flaccid stretched and erect length of the penis.
Nomogram for flaccid, flaccid stretched and erect length of the penis. Image credit: Veale et al/BJU International

Moreover, “the average flaccid circumference was 9.31 cm [3.66 inches], and the average erect circumference was 11.66 cm [4.59 inches],” they noted. “There was a small correlation between erect length and height.”

If you’re shocked by how, well, small those numbers are, you’re probably not alone: most people with penises think the average is at least 15.2 centimeters (6 inches) when erect. And yet, even these littler averages might be overstated: after all, you can’t exactly force someone to let you measure their dick, and that means even the best studies relied on volunteers – volunteers who, you have to assume, were confident enough in their size to bare all in front of a stranger.

“Most men tend to believe they're smaller than average, and there's some distortion about what reality is,” Morgentaler said – adding that he hasn’t seen “probably […] a single [patient] who hasn't paid attention to his penis size on some level.”


In fact, anxiety over being “big enough” is so prevalent that it can literally warp the data: studies into mean penis length which rely on self-reporting tend to come up with a result more than an inch larger than those which use actual, you know, tape measures. In a particularly cruel twist of fate, these reports are often then used as evidence of a person’s penile petiteness, just compounding the problem further. 

“It is helpful to normalise the situation,” Wylie advised. “Many men either lack any information or have been misinformed.”

But as any statistician will tell you, the raw mean is only half the information. It’s also important to look at things like the standard deviation and distribution of a dataset – and it’s here that we can see something even more reassuring. 

“What's interesting is, when you look at the curves, you see that most penises actually are fairly similar in size,” Morgentaler, who was not involved in the research, pointed out. “You really have to go to the extremes – the top or bottom 5 or 10 percent – to really see some big differences. And truthfully, in my practice, I would say that's exactly right. Most men have penises roughly the same size.”

And yet – does it matter?

Hopefully, there are some readers out there who are feeling quite relieved right now, having found out they’re packing a heftier punch than they previously believed. But for others, we bet you’re not feeling all that different at all.

“Seeing a graph of the distribution of shapes written in centimeters is nowhere near as compelling and as persuasive as the penises you see in porn,” countered sex researcher and educator Emily Nagoski. “So until I see an array of average, normal-size penises right there in front of me, how am I going to know what it actually means that the average penis is however many centimeters it is?”

In fact, even those convinced by the graphs may not feel too reassured. For many men, it seems, the problem isn’t that they’re poorly endowed, but that they’re not Ron Jeremy: one 2014 study found that even those who thought of themselves as “average sized” wished they were larger, stating an average ideal length of 18.47 centimeters (7.27 inches).

Now, we can see in the graph that such a length would put anybody firmly in the “monstrous” category of dick size – it’s practically off the chart. And yet, as one scholar put it back in 1978, “it is not too much of an exaggeration to say that penises in [men’s] fantasyland come in only three sizes – large, gigantic, and so big you can barely get them through the doorway.”


Perhaps that’s why so many men are turning to professional – even surgical – “solutions” for their genital unhappiness. “Urologists are constantly approached by men who are concerned about the size of their penis, despite the fact that the majority of them are normal sized” said Paolo Gontero, Associate Professor of Urology at the University of Turin, back in 2011.

But such procedures are not advised by experts, he added. “Surgery is characterized by a risk of complications and unwanted outcomes and lack of consensus among the medical profession on the indications for surgery and the techniques used.”

Instead, many specialists hope that with better information and understanding, doctors will be able to counsel those with so-called “small penis syndrome” – offering them a better idea of what is normal, rather than a complex over a non-existent problem. Others point to the severely lacking sexual education in the West, particularly in the US, as a reason some men – particularly, these days, younger people – are forced to rely on porn for their “facts” about what is normal.

“I think information is powerful,” Morgentaler concluded. “I think there's value in the data.” 


“It's worthwhile for men to know that the amount of variation for about 85 or 90 percent of the male population for penis size is all centered around pretty much the same number.”


  • tag
  • anatomy,

  • penis,

  • male,

  • penis size,

  • genitalia,

  • reproductive system