Does Penis Size Really Matter? Myths and Realities on Ideal and Average Penis Size

Does penis size matter?

For many men around the world, one very personal subject has often been a cause for worry: the size of their penis.

These concerns are caused by many things, including the amount of false ideas there are about:

  • what the average penis size is
  • how important penis size is to sex
  • what penis size means to how you feel as a man

Many people do believe that penis size matters, so we decided to take a closer look:

  • In what ways does penis size matter?
  • Who feels it matters the most, and how has this affected male self-image?
  • Do men really have that much to worry about?

We surveyed thousands of people, both men and women, to get a better picture of what the world thinks about this question. Read on to find out how much size really matters.

What is the average penis size?

The results of a 2015 review of studies on penis size that included over 15,000 men from around the world showed that the average penis length when erect was 13.12cm.

What do people think is the average and ideal penis size?

Many people do not have an accurate idea of what size penises usually are. We asked both men and women to guess what the average penis length is. The average of those guesses was:

  • women: 13.8cm
  • men: 14.1cm

When asked what the ideal length was, the average of the answers was:

  • women: 15.8cm
  • men: 16.6cm
Perceived average penis length

It’s clear that what we think and expect does not always match up with reality. Both men and women believe that the average penis is longer than it is.

But perhaps more worrying is the difference between what we think the ideal length should be. A woman’s ideal penis length was 2cm greater than the average length, and men felt it should be 2.5cm longer.

Average and ideal penis size by country

We asked men and women in the US and 9 European countries what they thought the average and ideal penis length is.

Perceived average penis length by country

One thing was true among all of the countries: the ideal length was greater than the average size, showing how many people believe that even an average penis may not be ‘big enough’.

But the gap between ideas of average size and ideal size was very different across countries. The sizes were the closest in the Netherlands where the ideal length came out as 15.1cm, only 1.1cm longer than their idea of the average length. In the US, these sizes were the furthest apart. Americans guessed an average length of 14.3cm, and suggested an ideal length was much greater at 17cm.

Average and ideal penis size by European country

Across Europe, major nations show a large difference in their ideas of what the average penis length is.

  • Poland had the highest guess for average length at 15.7cm, and the second-highest ideal length of 17.3cm
  • Austria took 2nd-highest guess of average length at 15.6cm, but was top spot for suggestions for ideal size at 17.6cm
  • UK had both the lowest guess for average size at 12.4cm, and the lowest ideal length at 14.2cm

Even though the stated ideal penis size ranged from 14.2cm to 17.6 cm, all European nations agreed on one point: the suggested ideal penis size was higher than the guessed average size.

Perceived average penis length by European country
Perceived ideal penis length by European country

Average and ideal penis size by US state

Average penis size by US state

We also took a closer look at guesses at average penis size across US states. This showed that there’s as much difference among states as there is among different countries.

West Virginia offered the lowest figure, guessing an average length of 12.8cm, and Arizona and Nebraska were close runners-up with a guess of 13.4cm each.

At the other end, Maine had the highest guess in the nation: an average length of 16.5cm, almost 4cm greater than West Virginia. Idaho offered the 2nd-highest guess at 15.9cm, and Hawaii was 3rd with 15.7cm.

Overall, there seemed to be no clear regional trend to these estimates. Almost every area of the US had different ideas of the average penis size.

Perceived average penis length by US state

Ideal penis size by US state

Similar patterns to average size were seen in the US states' thoughts on an ideal size. West Virginia, which was in last place for guesses of average size, was 2nd-last for ideal size with an average of 15.3cm.

Maine was 1st in the nation for guesses of average length (16.5 cm) as well as for ideal length at 19.3cm, a difference of almost 3cm. This was followed by Kansas at 18.6cm and Arkansas at 18cm. Altogether, the US shows an even greater range of beliefs about ideal penis size than it does about average size.

Perceived ideal penis length by US state

Does penis size matter to men?

How do men actually feel about their penis size? We asked men from 4 age groups to say what their level of satisfaction is with the size of their penis.

Overall, most men were pretty happy with their size:

  • 14% were very satisfied
  • 44.5% were satisfied
  • 29.5% were neither satisfied nor dissatisfied
  • 10.3% were dissatisfied
  • 1.7% were very dissatisfied
Male satisfaction with penis size

Given that men across the world have very different ideas about average penis length, it’s surprising to see that most are happy with their bodies.

The number of men who said they were satisfied with their size was quite different across the age groups. While 39.4% of men aged 18 to 24 reported being satisfied, this increased to 51% among men aged 45 and over. The proportion who were very satisfied showed little change overall, starting at 15.7% of those aged 18 to 24 and growing to 16.9% of men aged 35 to 44, before going down slightly to 13.5% of men aged 45 and over.

Levels of dissatisfaction seemed to go down more significantly with age. 13.1% of men aged 18 to 24, but only 7.7% of men aged over 45, reported being dissatisfied with their size. And while 3% of men aged 18 to 24 noted that they were very dissatisfied, this fell to 0% of those aged 45 and over.

Does penis size affect confidence?

We also wanted to find out just how much these concerns over size affected men's confidence in their sexual ability. Similar to satisfaction levels about size, 59.4% said size did not affect their sexual confidence.

Another 24.7% noted that their size made them feel more confident. Only 15.8% said that the size of their penis had lowered their sexual confidence.

Effect of male penis size on sexual confidence

Most men do not seem to be affected by the differing opinions on what is an ideal penis size.

Sexual confidence related to penis size appears to go up as men age. While 57.6% of men aged 18 to 24 said their size does not affect their sexual confidence, this grew to 65.4% of men 45 and over. Similarly, among men aged 18 to 24, 16.2% felt that their penis size had lowered their sexual confidence – but this fell dramatically to only 10.6% of men aged over 45.

Penis size and erectile dysfunction (ED)

Worries about penis size can have a real effect on men's sexual lives. Anxiety can make it harder to get and keep an erection, which is a condition known as erectile dysfunction (ED). ED is not related to the actual size of your penis but if a man feels uncomfortable about his size, this can cause ED, or make it worse.

Having ED can, in turn, create even more anxiety and lower sexual confidence. This may be more noticeable in younger men, as young men in our study showed less satisfaction about their size and a greater impact of size on their sexual confidence. A recent study showed that 1 in 4 cases of ED were in men under 40.

We asked the men in our study how frequently they experienced symptoms of ED. While 70.2% of men aged 18 to 24 said they’d never had ED, this meant that a surprising 29.8% did sometimes experience these symptoms – and 10.6% experienced ED during half of sexual encounters or even more often.

ED can become more common as men age. Our findings showed this, with the number of men who’d never experienced ED going down from 70.2% among those aged 18 to 24 to 57.7% among those aged 45 and over.

Those who had ED symptoms less than half of the time grew from 19.2% of men in the youngest group to 26% in the oldest. But even among older men, a high amount of ED symptoms was still quite uncommon: 7.7% of men aged over 45 had symptoms half of the time, 4.8% experienced ED more than half the time, and only 3.8% said they experience these symptoms every time.

Percentage of men experiencing symptoms of erectile dysfunction

What do women think about penis size?

One of the biggest worries for men is what their sexual partners think of their penis size. To get a better idea of how realistic those worries are, we asked the women in our study how much they value penis size.

67.4% said that size is somewhat important and not a major concern to them. A further 21.4% felt that penis size was simply not important. Only 11.2% of women said that size was very important to them.

So size is not important to a lot of women. And when asking if size matters to women, it is not nearly as much as many men think.

➤ ZAVA also researched the average breast size. You can explore our findings on "Does Breast Size matter?"

Importance of penis size to women

Tips for a healthy, happy sex life

There is a lot of social pressure around penis size. And ideas about penis size are very different to reality. These ideas differ again across different nations. But as we've found, most men continue to show satisfaction with their size, and most women do not consider size to be an important issue.

At the end of the day, there's much more to satisfying relationships and sexual confidence than this one simple measure.

At ZAVA, we believe that you should feel proud of your body and your sexual health. We offer a range of health services for sexual concerns, like treatment for Erectile Dysfunction and premature ejaculation, as well as confidential STI testing. Our services are run by doctors, who can give advice or prescribe medication, to be quickly delivered to your home.


We surveyed 2,121 respondents on questions relating to sexual health and ideals of male penis size. 1,148 respondents identified as male, with 973 respondents identifying as female. Of these respondents, 1,055 were from the US and another 1,066 were from Europe. Of European respondents, 489 were from the UK. States represented by fewer than five respondents and countries represented by fewer than 10 respondents were omitted from map results. Age ranges of: 45 to 54, 55 to 64, 65 to 74, and over 75 were grouped into the over-45 age range due to a small number of respondents (237 total).

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