Average Penis Size: What's Normal?

It's smaller than you probably think

People often have varying guesses about what the average penis size is. According to research review involving more than 15,500 people with penises, the average length of a flaccid (soft) penis is 4.59 inches, while the average length of an erect (hard) penis is 3.66 inches.

Data aside, perceptions about "normal" penis size differ quite a bit. Many wonder whether the size of their penis is what should be expected for their age, weight, or even race.

This article offers key facts about average penis size, including factors that influence it and whether you can change how "big" you are.

It also explores how concerns about penis size can affect relationships and personal well-being, and how your partner's perceptions about penis size may be different than yours.

pants with a tape measure

Riou / Getty Images

What Is the Average Penis Size?

Statistically, the average length of an erect penis is 6 inches, while the average circumference (girth) is 5 inches. The average flaccid (soft) penis measures 3.6 inches in length with a girth that is roughly the same.

You can measure your penis with a ruler or tape measure. Here are some tips to ensure an accurate measurement:

  • When the penis is erect, measure from the tip of the penis to the pubic bone, placing the ruler on the top side of the penis.
  • To measure the circumference, wrap the measuring tape around the middle of the shaft. If you are using a ruler, wrap a piece of string around the shaft and measure that instead.

Am I a "Shower" or a "Grower?"

Another popular belief is that some flaccid penises can "grow more" than others during an erection. This suggests that flaccid penis size has little to do with erect penis size. This is largely true.

A 2018 study in the International Journal of Impotence Research looked at two groups: one whose penises grew less than 1.5 inches from a flaccid to erect state ("showers") and those that grew more than 1.5 inches ("growers").

What they found was smaller flaccid penises grew more than larger flaccid penises, with all groups averaging an erect penis length of around 6 inches.

In the end, the flaccid size of a penis is not a good predictor of its erect size. Moreover, penis size is not static and can change with temperature. When exposed to cold, a flaccid penis will shrink in size to conserve heat. Older age can also lead to a reduction in penis size.

Factors That Influence Penis Size

There are not many things that can influence penis size, other than perhaps genetics. Penis growth is largely influenced by a surge of testosterone during puberty, typically between the ages of 10 and 14. The penis may continue to grow until a person is around 21. After that, penis size is largely "set."

Despite what some people may tell you, a person’s foot size, nose size, height, and weight have little to do with their penis size. With that said, a person's height and weight may create a false impression of what the penis size actually is.

A 2013 study from Australia found that taller men with an average-sized penis were perceived to have a "smaller" penis than shorter men with the same size penis. The same was seen when comparing overweight men to men who were slim.

Race and ethnicity play a role in penis size, but the association is not straightforward. When looked at as a whole, the difference in average penis length between Black men, Latinx men, Asian men, and White Men is not all that significant.

Can Penis Size Change?

Diet, pills, and exercise do not in any way influence the size of the penis. The same applies to "penis enlargement" devices like penis pumps, which do little, if anything, to increase the length of the penis. They may increase girth if used excessively by creating scar tissues, but they can also cause permanent numbness.

One of the things that can change penis size is surgery. Some procedures, like radical prostatectomy (removal of the prostate), can shorten the penis. To remedy this, a surgery known V-Y plasty may be used to increase penis length by cutting the ligament that anchors it to the pelvic bone. (Even so, V-Y plasty can destabilize the penis and cause it to turn uncomfortably while erect.)

One other common condition that can decrease penis size is Peyronie's disease (PD). PD typically affects older men and causes the penis to curve abnormally. Scar tissue can develop at the site of the bend, reducing penis length by as much as a half-inch.

Prolonged celibacy may also cause penis size to shrink.

Concerns About Penis Size

For better or worse, the size of a penis can greatly influence a person's confidence when it comes to having sex. With that said, there is often a mismatch between how someone with a penis views themselves and how a potential partner sees them. This is especially true if the person thinks that their penis is "too small."

According to a study published in the Journal of Health Psychology, around 68% of men surveyed said they had concerns about their penis size. The concerns are largely driven by unrealistic expectations in the media—as well as society at large—about what is an "average-size" penis. This is a problem.

Some people feel self-conscious about the size of their penis and want to know what's normal. The average size is probably smaller than you actually think.

While the size of a penis generally does not directly affect sexual function, it can increase the risk of sexual problems. Studies have shown that people who think their penises are small are more likely to have low self-esteem, performance anxiety, relationship problems, and erectile dysfunction. They are also less likely to let others, including doctors, look at their penises.

How Much Does Penis Size Matter to a Sex Partner?

Many people have been conditioned to believe that "size matters" and will experience stress if they feel they fall short. They may also believe that they will be more attractive to a partner (or perceived to be more masculine) if they have a larger penis. This is largely untrue.

According to a 2015 study in PLoS One, cisgender women shown photographs of erect penises preferred a penis size of 6.4 inches for a one-night sex partner. For a long-term partner, the preference was slightly smaller: 6.3 inches.

Other studies have found a disconnect between what female and male partners feel about penis size. In a study of heterosexual people published in the British Journal of Urology International, 85% of women were satisfied with the size of their partner’s penis, while 45% of men thought that their own penis was too small.

The dynamics are slightly different in men who have sex with men (MSM). Penis size commonly factors into who takes the insertive ("top") or receptive ("bottom") role during sex.

With that said, MSM are 50% less likely to regard their penises as "small" compared to heterosexual men and far more likely to regard them as "above average" (35% versus 22%).

When Is a Penis "Too Big?"

Having a larger penis may not always be a good thing. In fact, a 2015 study found that, among 75 women surveyed, one of every 15 had left a relationship because their partner's penis size was "too large."

There are other concerns. A large penis—particularly an uncircumcised penis—is linked to a higher risk of bacterial vaginosis (BV), an infection of the vagina, in part because the increased friction against the vaginal wall damages tissues and allows more bacteria in.

A larger penis poses similar risks in MSM who have anal sex, including an increased risk of HIV.


Concerns about penis size can cause stress and lead to sexual dysfunction in men who think that their penises are small. The problem is that many men think that the "average penis" is larger than it actually is.

In fact, the average length of the male penis is 6 inches, while the average girth is around 5 inches. Studies suggest that women tend to prefer penises of this size compared to a large penis.

Once puberty is completed, the size of a penis is largely "set." While certain things can reduce the size of a penis, such as surgery or Peyronie's disease, there are few that can effectively increase it.

A Word From Verywell

It is important to remember there is no “normal” when it comes to penis size. If you are worried that the size of your penis does not meet your partner's expectations, talk to a doctor or a therapist who can help you gain a better perspective.

While it can be difficult to discuss penis size with your partner, you can take a different approach and ask your partner what they enjoy sexually. Try focusing on intimacy and connection, which many women find just as important as sex.

Frequently Asked Questions

  • When do penises stop growing?

    Penises usually stop growing by the time a male completes puberty, between the ages of 18 and 21.

  • What factors influence penis size?

    Genetics plays the largest role in determining penis size. However, other factors contribute, including hormones like testosterone. Certain genetic conditions like Klinefelter syndrome can impair testosterone production in boys.

  • Does penis enlargement work?

    There is little evidence that things like penis pumps or traction actually work. Moreover, the improper use of these products can cause injury that affects penile function. The same applies to fat injections and surgeries like V-Y plasty that may nominally increase penis girth or length but can also cause deformity or instability.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By S. Nicole Lane
S. Nicole Lane is a freelance health journalist focusing on sexual health and LGBTQ wellness. She is also the editorial associate for the Chicago Reader.