What Is the Average Penis Size?

Medically Reviewed by Poonam Sachdev on November 10, 2022
5 min read

If you have ever been concerned about your penis size, you're not alone. The size of the male sex organ has long been thought to be an indicator of a person's testosterone levels and sexual abilities. But this is a myth. 

Many men wish their penises were larger when in reality they have normal-sized penises. Studies have found that most women are satisfied with their partner's penis size. So, if you have similar worries, know that your penis may be in the average range. And even if it isn't, it by no means reflects your masculinity or your ability to sexually please your partner.

Sex organs like penises grow during puberty, which usually starts between the ages of 9 and 14 in males and extends for another five years. This means your penis would have grown to its maximum size by the time you reached your 20s. 

If you are wondering what is the average penis size at this age, the answer may surprise you. Most people with male sex organs believe that an average penis measures 15.24 cm (6.0 inches) or more when erect. This belief is partly spread by popular studies relying on self-reported measurements. Since men often judge their sexual attractiveness based on their penis size, it's common to provide incorrect data during such studies to appear socially desirable.

However, a few studies have been carried out in the past decade in which penis size measurements were taken by health experts using standard procedures. According to those studies, these are the average sizes of penises in their different states:

  • Flaccid penis length: 9.16 cm (3.61 in)
  • Flaccid stretched penis length: 13.24 cm (5.21 in)
  • Erect penis length: 13.12 cm (5.17 in)
  • Flaccid penis girth: 9.31 cm (3.67 in)
  • Erect penis girth: 11.66 cm (4.59 in)

Men with male sexual partners may not find these numbers surprising. Studies show that such men have more accurate ideas of average penis sizes, since they are exposed to greater numbers of penises and much more intimately.

Genetics is the most important predictor of your penis size. Just as your eye and skin color are determined by your hereditary factors, so is your penis size. Studies have found another factor to be a strong indicator of flaccid penis size — height. Not surprisingly, your height is also determined by your genetics.

Besides such macro factors, these micro factors could influence your penis size: 

Hormones. If any hormonal issues arise during pregnancy, they could affect the body of the fetus, including the penis of a male child. For example, this can happen if the expectant mother produces too little human chorionic gonadotrophin (hCG), a hormone needed to develop testosterone in the fetus. Abnormalities in penis size could also occur if the fetus couldn't respond to testosterone, a condition called androgen insensitivity. 

Nutrition. Malnourishment during the time of pregnancy could prevent the fetal penis from growing properly. Similarly, teens who don't get enough nutrition at the time of their puberty could have delayed puberty — a condition known to cause smaller testicles and penis.

Environmental chemicals. Many environmental chemicals including fertilizers, plasticizers, pesticides, and phthalates can negatively affect penile development in the fetus. This happens because they act as endocrine disruptors and inhibit the production of hormones in the fetus.

Various myths are associated with penis length. For example, many believe foot size and masturbation habits affect penis size. But research hasn't found any evidence for this.

Knowing how to measure your penis size correctly is important so that you can buy condoms that fit. To measure the size of the penis, you should consider not only the length of the organ from the tip to the pubic bone but also its girth (where it's the widest). This is especially crucial in countries like the United States where manufacturers categorize condoms by their length and girth. 

Before you begin measuring, your penis should be erect, and you should have a measuring tape, a ruler, or a piece of string at hand.

To measure the length of your penis, follow these steps:

  • Press the measuring device into your pubic bone so that it's positioned right at the base — where your penis attaches to your body. This is all the more important in those with belly fat.
  • Measure your erect penis from the base to its tip.

To measure the girth of your penis, follow these steps: 

  • Take a non-stretchable piece of string or a soft measuring tape. A string that stretches could lead to measurement errors.
  • With gentle hands, wrap the string or tape once around the thickest part of your erect penis.
  • Check where the ends of your measuring instrument meet. Make a note of it if it's a tape. If you're using a string, mark where one end meets the rest. 
  • Straighten out your tape or string. Measure the length from the end to the mark using a ruler.

Many people look for ways to enlarge their penises. There are several penis-enlargement methods and products available that claim to increase penis size. However, research does not support these claims. In fact, these techniques can damage your body.

These are some popular techniques said to increase penis size:

Surgery. Studies of penile-enlargement surgeries show mixed results in their effectiveness, their safety, and patient satisfaction. Such surgeries, like penoplasty, can at best add slight length to a flaccid penis or slightly increase the penile girth. They don't affect the actual length of an erect penis. After undergoing surgery, you can face complications like scarring, infection, and loss of function. This is why experts consider such surgeries “highly risky".

Vacuum pumps. These are often used by those with erectile dysfunction. By drawing blood into the penis, vacuum pumps make penises swell temporarily. But they have no long-lasting effect on penis length or girth. Moreover, their repeated use can prevent you from getting firm erections by damaging the elastic tissue in your penis.

Supplements and pills. These products usually contain minerals, vitamins, or hormones like testosterone. While there's no scientific proof that they work, some studies have found them to be harmful when taken continuously.

Exercises. Those not satisfied with their penis size often attempt stretching exercises like jelqing, in which you push the blood by hand from the base to the tip of the penis. While these exercises are safer than other techniques, there's no evidence that they work. They also risk scarring, disfigurement, and pain when done the wrong way.

Studies show that many men are concerned about their penis size and believe it to be smaller than those of others. If you feel the same, it could be because you too consider penis size a reflection of your masculinity and sexual abilities. 

In reality, several studies show that penis size tends to be much less important for women than for their male partners. Moreover, since men often underestimate their penis size, your worries about size are likely pointless. Still, if the thought of your penis size makes you anxious or stresses you out, you can talk to a therapist or a mental health expert about your concerns.