Medically reviewed by Patrick Carroll, MD
Written by Our Editorial Team
Last updated 1/19/2021
Worried about your penis size? Relax, you’re not alone. At some point, just about every guy has wondered how their penis stacks up compared to the average.
Like many aspects of sex and anatomy, penis size is a subject that creates distorted perceptions of what’s “normal.” Most studies of penis size around the world show that the average penis size is, to put it simply, not quite as big as people may think.
According to a review of study data by researchers at King’s College London, the average flaccid penis measures 3.6 inches from base to tip.
When it comes to the circumference (the circular measurement around the penis), the average man is about 3.7 inches soft.
Erect, the average penis length is about 5.2 inches, with an average circumference of about 4.6 inches.
Not quite what you’d expect, right? From harmless bragging to porn-induced expectations about penis size, there are numerous factors that contribute to the belief that the average man’s penis is, well, bigger than the real average.
In this guide, we’ll look at some more of the data behind the average penis size. We’ll also look at whether or not dick size (or lack of size) is really an issue that you should spend your time thinking about.
Penis size is a common source of anxiety for men. Because of unrealistic expectations about what is and isn’t normal perpetuated by media and pornography, a surprising number of guys worry about whether or not their penis is big enough.
In an effort to help clinicians dealing with Body Dysmorphic Disorder and men feeling anxious about their dick size, researchers at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's College London completed a thorough review of study data about penis size.
The review, which can be viewed online here, is currently the most comprehensive study available on penis size, drawing from a total of 20 studies with more than 15,500 participants.
As stated above, the researchers found that the average penis size -- using a sample of more than 15,500 men -- was 3.6 inches (9.16 cm) when flaccid and 5.2 (13.12 cm) inches when erect.
The study data should come as a relief to many men, confirming that the “six inches” average that’s often promoted in media or casual conversation isn’t even close to the reality of penis size.
What’s particularly interesting is the difference between the real data on penis size and the perceived average penis size people report when surveyed.
In a survey conducted by UK company Health Bridge Limited, researchers asked people to state what they believed the average penis size was. The survey featured men and women, drawing data from thousands of people located throughout Europe and North America.
The average penis length given by participants varied by country, with Poland reporting the biggest perceived average penis length at 6.18 inches (15.7 cm). Austria, Italy, Germany and the United States all featured estimates well above the real average, at 6.14 inches (15.6 cm), 6.02 inches (15.3 cm), 5.83 inches (14.8cm) and 5.63 inches (14.3 cm), respectively.
For the most part, survey participants overestimated the average penis size by about half an inch to one inch (1.3 to 2.5 cm). Of the 10 most widely surveyed countries, only the UK guessed an average size below the real average, estimating that the average erect penis is 4.88 inches (12.4 cm).
The survey data shows that most people overestimate the average erect penis size, often by a significant amount -- a fact that can create anxiety, frustration, and insecurity for many men.
In the same survey, women were asked how important penis size was to them in a partner. The survey respondents were given three options to choose from: very important, somewhat important and not important.
The overwhelming majority of female survey participants, 67.4%, said that penis size was only somewhat important to them -- that it wasn’t a major concern or of overriding importance in their choice of partner.
Another 21.4% of female participants said that penis size wasn’t important at all. In fact, only 11.2% of women that responded to the survey said that penis size was very important to them when choosing a romantic partner.
Scientific study data also seems to support the idea that penis size just isn’t a major issue for most women. In a 2015 study of penis size and sexual attraction (all participants were residents of California, 18-65, sexually experienced), researchers found that only 27% of women had ended relationships, in part, due to a difference between their preferred penis size and the size of their partner’s penis.
>>MORE: Sexual Performance Anxiety and ED: What You Need to Know
Well, fellas, you knew this section was coming. While we’re not really in the business of making men feel, ehm, inadequate, we also understand that some men simply need to know. We get it. That said, there aren’t any CDC rules or clinical guidelines to follow when trying to accurately measure the size of your penis. Luckily, it doesn’t appear to be rocket science, either.
If you want to get an accurate measurement of your penis — for scientific purposes, of course — here are some practical tips:
First, decide whether you want an erect measurement or a flaccid measurement. You can do one or the other, or both — it’s a free country.
When you’re ready to measure, take a ruler and place it at the base of your penis.
If flaccid, take the tip of your penis and, without pulling or extending it, hold it to the ruler’s edge to find your measurement
If erect, carefully place the ruler’s edge against your penis and observe your measurement.
To find the circumference:
Take a piece of smooth thread or dental floss (we personally recommend against twine to avoid scratching your penis skin) and cut it to a length of a few inches.
Whether flaccid or erect, find the widest part of your penis, and gently wrap the thread around it, making sure to carefully note where the thread intersects.
Carefully remove the thread from around your penis, while making sure not to lose track of where the piece intersected with itself.
Place it on top of a ruler, and find your circumference in inches.
And there you go. Simple enough, right?
Certain aspects of your body can be changed through things like diet, exercise, medication and grooming. Penis size -- save for factors such as erection quality -- generally isn’t one of them.
Combine this with the fact that the vast majority of people overestimate the average penis size and that the vast majority of women simply don’t care about penis size, and it quickly becomes clear that the best approach is to not fret too much about your dick size.
Instead, a better approach is to focus your time, energy and effort on improving the aspects of your sexual performance and appearance that you do have control over, from preventing hair loss and improving grooming to increasing your erection quality, and most importantly, taking care of yourself.
The takeaway here, fellas, is that you might be concerned about your penis size, but it’s likely that your partner is perfectly happy with you. However, if you’re interested in measuring your size and seeing where you stack up according to the data, the process is simple enough and doesn’t require any specialized tools.
If you’re worried about your performance in the bedroom, the best thing to do is talk to your partner/s. Have a conversation. If you’re still worried, there are other options.
While you can’t really change what you’re working with down there, you can ensure peak bedroom performance. Schedule a virtual visit with one of our certified healthcare providers to find out how you can get hard — and stay hard. And while you’re here, don’t forget to check out our blog, How to Get an Erection Faster and Stay Hard Longer.
Insider tips, early access and more.