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What’s the average penis size? Probably smaller than you think

Felix Gussone, MD - Contributor Avatar

Reviewed by Felix Gussone, MD, Ro, 

Written by Michael Martin 

Felix Gussone, MD - Contributor Avatar

Reviewed by Felix Gussone, MD, Ro, 

Written by Michael Martin 

LAST UPDATED: May 19, 2023


A lot of guys have some anxiety about the size of their penis, but statistically speaking, most guys have an average-sized penis. How big is that? Probably not as big as you think. 


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Average penis length

A 2015 research review found that the average erect penis size is 5.17 inches long (13.12 cm). For a flaccid penis, that size goes down a bit to 3.6 inches (9.16 cm) long on average.. 

Why, then, do most men think the average penis size is more than 6 inches long? We can thank a researcher named Alfred Kinsey for that. He and his colleagues published a report in the 1960s that claimed that the average penis size was over 6 inches, and unfortunately, that problematic number has buried itself deep in our psyche. After more extensive research on the topic, we now know that it was an overshoot of about 20% beyond the actual number.

Average penis girth

Penis girth—aka the circumference, better known as “how thick it is”—gets a lot of attention in the world of men’s sexual health. The average erect penis circumference (aka “girth”) is 4.59 inches (9.31 cm), and the average girth of a flaccid penis is 3.67 inches (9.31 cm). 

What is considered a big penis?

Now that we know the average length and girth of a penis, you might ask yourself if you have a big penis, or a small penis. When it comes to penis size, “big” or “small” are not a clearly defined word, and what one considers big or small is informed by things like insecurities, preferences and self-image. When talking about penis sizes, it’s better to call anything above 5.17 inches erect length and 4.6 inches erect girth “above average”, and sizes below these numbers “below average”. 

Keep in mind that even if you’re a bit below average doesn’t mean that you have a small penis. Either way, it’s important to note that there are a lot of other factors that contribute to being “good at sex” than just penis size.

How many guys have 7 inches or more?

It’s rare. Super rare. According to the available research, just one in a hundred guys have a penis that measures between 7–8 inches erect. 

Numerous studies have found that Kinsey’s original estimate of 6 inches is around a full inch longer than average. While we’ll take his findings with a grain of salt, Kinsey’s other research showed that extremely large penises (over 7–8 inches) are exceedingly rare. In fact, the original Kinsey penis-size survey found that only:

  • 1% of men have a penis between 7–8 inches  

  • 6 in 1000 guys (0.6%) have a 9-inch penis

  • Just over 0.2% of guys have a penis larger than 9 inches—that’s 2 in 1000

Up to 90% of male penises are within an inch of the average size. Statistically speaking, that means most guys have a normal-sized penis. No, really. Your penis is most likely within the normal range. 

How to measure your penis

Knowing your penis size, and knowing how to measure your penis correctly, not only has a potential impact on a man’s confidence. It is also important when it comes to choosing the right condom size. In fact, when choosing the right condom might be the only instance where size actually matters: if your condom is too tight or too loose it can cause performance issues, such as condom-associated erectile problems and an inability to ejaculate

To identify what size condom you need, you should measure the length and the girth of your penis with a tape measure. Once you know these two measurements, you can check different brands in the store or online and choose a condom that most closely matches your erect penis size.

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How to make your penis bigger

While most penises are a perfectly adequate size, many men are still unsatisfied with the size of their penis and want to find ways to make it bigger. If your penis falls in the normal range but you’re still bothered by the size of your penis, you may have what some researchers call penis anxiety or penis dysmorphic disorder (PDD—a type of body dysmorphic disorder). 

In some cases, though, especially if you’re in the rare group of people with a micropenis, penis enlargement procedures or devices may be able to help. 

Does penis size matter? 

The size of your penis almost definitely matters more to you than to anyone else, including your sexual partner or partners. One large study showed that only about 50% of men are satisfied with their penis size, while a whopping 85% of women are satisfied with their partner’s penis size. 

A lot of myths and stereotypes link penis size to race, hand size, or even shoe size. But there just aren’t enough credible studies to back up any of these claims. Most guys have a penis that’s within an inch of the average size, so you’re probably right where you need to be. If you still have concerns, you can speak with your healthcare provider about the options available. 


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

May 19, 2023

Written by

Michael Martin

Fact checked by

Felix Gussone, MD

About the medical reviewer

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.

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