What’s the Average Penis Size?

Written by
The Manual Team
Medically approved by
Dr Earim Chaudry
Last updated
22nd November 2021

In 30 seconds…

We tend to have unrealistic ideas about how big our penises should be. Both pornography and low self-esteem can skew the truth. Because, the truth is: most men have average-sized penises (that’s why it’s called ‘average’). More importantly, penis size matters much less than you might think.

Men have always placed a lot of value on the size of a penis. From ancient times to the present, different cultures have had different ideas on what constitutes the ideal penis size. If the ancient Greeks thought the smaller the better, the Vikings sought serious size.

However, the “ideal” necessarily hid a lot of major differences – just as it does today. And when you feel as though you do not compare well to the norm, it can be a difficult experience. It can even take its toll on your long-term mental health.

So, to cut through the noise on this contentious topic, what is the average penis size? In this article, we’re going to be discussing exactly that: our perceptions of average size, the realities, and why size might not be as important as you fear.

What is the Average Size for a Penis?

To begin with, the average penis size is probably not as large as you think. Studies have shown that people continually overestimate the average size of a penis. Women add over half a centimetre to the real average, whilst men believe that average penis size is a full centimetre more than it actually is. 

According to the largest study of penis size – a review of studies involving over 15,000 men – the average length when erect is 5.16 inches. The average girth, or circumference at the widest part, is 4.59 inches. This translates to about 13.12 cm length and 11.66 cm girth.

For flaccid penises, the measurements were 3.61 inches (9.16 cm) in length and 3.66 inches (9.31 cm) in girth.

Whilst these figures were the averages across the board, the study also broke down the 15,000 men into percentiles, showing what percentage of men had a size over a given measure. An erect 6 inches (15.24 cm) was at the 90th percentile, meaning that only 10% of men had a penis larger. Meanwhile, only 10% of men had a penis smaller than 4.33 inches (11 cm).

How to Measure Your Own Penis

You may have read different figures originating from different studies. However, besides being the largest, this review of studies ensured to only include other studies in which the participant’s penises were measured by a doctor.

This was because one of the main problems involved in gaining an accurate sense of average penis size is that men do not measure their members in the same way. Meanwhile, some studies where men were trusted to self-report their length did not give accurate results. For example, another review of studies – in which men reported their own penis length – noted that the average self-reported length was 1.26 inches longer than when a doctor measured it.

To measure your penis correctly, first take yourself a soft measuring tape. Rulers or hand-spans won’t do. Place one end of the tape at the pubic bone – i.e. the bone at the base of your penis – and compress any fat that you find there. Take the other end of the tape to your tip.

If measuring girth, wrap the tape around the widest part of your penis – either the middle or the glans.

Does Penis Size Actually Matter?

Sometimes, no number of figures and statistics can make a man feel better about their size. According to a study led by Dr Kevan Wylie, 45% of us are dissatisfied with the size of our penis – and that dissatisfaction is actually much more common in men with average-size penises than those with smaller ones. This may be the result of a cultural problem with the way that we compare our bodies to others.

In this respect, repeating the clichés like “size doesn’t matter” is not a very helpful response. To you, it may feel like it does matter – and in some cases, it matters a lot. Working towards a different perspective, in which your penis length is less concerning, may rather be helpful.

What Do Women Think about Penis Size?

For example, it can be helpful to know that women are much less concerned about the size of their partner’s – and sexual partners’ – penis than men are themselves. According to Dr Wylie’s study, 85% of women were satisfied by their partner’s size, whilst they much preferred a good personality and a desire in their partner to meet their sexual needs.

If anything, a wider penis was more important to women in the study than a long one. 90% of participants agreed.

How Does Porn Affect Your Sense of Average Penis Size?

Meanwhile, you may find that pornography affects your sense of what constitutes a “normal” penis size. In fact, nearly 40% of men in Dr Wylie’s study agreed that watching porn during adolescence may have contributed to the feelings of inadequacy felt about their size.

Watching excessive amounts of pornography can affect your ideas about sex and your anatomy. Whilst there is such a thing as porn-induced erectile dysfunction too, comparing yourself to the sizes you see in porn is not good for your self-esteem.

Can You Make Your Penis Bigger?

If you are concerned about the length of your penis, there are ways to make your penis appear larger.

Whilst it is commonly asked whether erectile dysfunction (ED) treatments like Viagra can make your penis larger, this is not exactly true. What ED drugs can do, however, is to help your penis to reach its full size.Meanwhile, trimming back your pubic hair can help your penis to stand proudly, whilst exercise can reduce the fat around the area that might be disguising its full size.

Key Takeaways…

The average penis size is 5.16 inches, or just over 13 centimetres. However, it is common for penises to range from 11 to 15 cm. The chances are that your penis is of a more normal size than you think.

Whilst we men have always worried about our size, women care much less. 85% of women are satisfied by their partner’s size – and hold to that old adage that it is more what you do with it that counts.

Trimming back your pubes or losing weight might make you feel better about your size. However, knowing that it is not the be-all and end-all can help too.


What is the average penis size?

Average penis size for an adult man is about 5.16 inches (13.12cm) long, when erect, with a girth of about 4.59 inches at the widest part (11.66cm). Flaccid, these penis size averages become 3.61 inches (9.16 cm) in length and 3.66 inches (9.31 cm) in girth.

Does size matter?

When it comes to penises, size doesn’t really matter. Whilst almost 50% of men report being dissatisfied or concerned with the size of their penis, most sexual partners report being quite happy with their male partner’s size. If anything, girth may be a little more important than length. But, even then, sexual satisfaction tends to come from communication and intimacy, rather than the size of genitalia.

Why are men unhappy with their penis size?

Studies suggest that watching pornography during adolescence can lead to future unhappiness with penis size, since pornography tends to highlight only those men with uncommonly large penises. On a wider, cultural level, the perception that bigger is better can be very damaging to male self-esteem, and can make us discontent with our penis size, when it is most likely quite average.

How do I measure my penis correctly?

To measure your penis correctly, ensure you are fully erect (strongest erections occur when you are most aroused). Then, take a flexible tape measure and measure along the top from the tip of your penis to the pubic bone (extend the tape measure past any pubic hair or excess fat until you meet the resistance of the bone). To measure girth, wrap the tape measure round the widest part of your penis whilst fully erect, and note where the two ends of the tape meet.

Can I make my penis bigger?

There are ways to enlarge your penis, by exercising to reduce excess fat, trimming your pubic hair, or even resorting to surgery. However, remember that your penis is most likely of an average size already, and that, ultimately, size does not matter.

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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