Does penis size matter? And how do I know what’s normal?

When it comes to penises, we seem unable to escape the idea that “bigger is better”. Popular culture and pornography constantly present us with unrealistic standards – that penises should be long, thick and hard.

This can skew ideas about what is “normal”. For example, one study found men believe the average penis measures 15.8 centimetres (or 6.2 inches) when erect.

But the evidence tells a different story.

So, let’s take a look: what is the average penis size? And can you tell from someone’s hands and feet? Is a micropenis just a small penis? And can penis size affect your sex life? Here’s what we know.

What is the average penis size?

In 2020, a review of all the available research on penis length found the average length of an erect penis is smaller than many people think: between 12.95 and 13.97cm (5.1–5.5in).

The researchers said taking bias into account – as people in studies often measured their own penises – the average was probably at the lower end of this range.

When flaccid, the average length is around 9.16cm (3.6in).

Average girth – also known as the circumference – is 9.31cm (3.67in) when flaccid, or 11.66cm (4.59in) when erect.

Keep in mind, these are just averages. Penises come in all shapes and sizes. This means wide variation – not only in length and circumference, but also shape such as curvature – is completely normal.

What is average can also vary across different regions of the world.

Growth in puberty

Reaching full sexual maturity occurs at a different pace for everyone. There is no fixed age when someone should reach their maximum penis size.

However the most significant changes occur during puberty. Before that, the penis will only grow slightly.

For most males, puberty begins between 9 and 14 years old. It involves hormonal changes, especially an increase in testosterone production in the testicles.

The first sign of puberty is usually when the testicles (also called the testes or “balls”) get bigger, followed by the penis growing.

These changes also trigger sperm production in the testicles, as well as erections and ejaculation.

Big hands, big … penis?

You may have heard that you can tell someone’s penis size by the size of their hands or feet. So, is there any truth to this?

Studies have looked at the relationship between penis length and finger length, foot size and testicular volume, but have inconsistent results.

However, there may be a link between how tall you are and the length of your erect penis.

Factors that may influence penis size include genetics, ethnicity, chronic diseases such as diabetes, smoking and hormonal factors.

What about micropenises?

Sometimes, a penis may not develop completely while the fetus is in the womb.

This may result in a micropenis, a condition generally diagnosed at birth where the penis is significantly shorter than average (2.5 standard deviations below) for the person’s age. For example, if a newborn’s penis is 1.9cm (0.75in) or shorter when gently stretched, this is considered a micropenis.

This condition is very rare, affecting less than two in 10,000 births. Micropenises may be caused by a variety of genetic or hormonal factors, but sometimes no cause is found.

Treatment with testosterone (usually as an infant) is generally effective at increasing the length of the penis. Surgery is only used in very rare cases.

Read more: A man lived to old age without knowing he may have had 3 penises

Does penis size affect your sex life?

Insecurity about size is unfortunately common.

One study of 52,031 heterosexual men and women found only 55% of men were satisfied with the length of their penis. About 45% wanted to be larger, while just 0.2% wanted to be smaller.

Anxiety often focuses on whether their sexual partner is satisfied. Yet the same study found 85% of heterosexual women were satisfied with their partner’s penis size. We also know the majority of these men would actually be considered to have a penis length within a normal range.

However dissatisfaction with penis size can have significant psychological impacts, such as feelings of shame and embarrassment.

Another study from 2010 surveyed 1,065 men who have sex with men, to understand how penis size affected their experience of sex and their sexual behaviour and health.

It found 65% were satisfied with their penis size. There was no link between penis size and the number of sexual partners someone had.

However men who self-reported smaller than average penises were more likely to identify as “bottoms” (receiving anal sex partners), while men who self-reported larger penises more often identified as “tops” (being the penetrating partner). Average size was linked to being “versatile”, that is, someone who is comfortable being a top or bottom.

This study also found self-reporting a smaller than average penis was associated with poorer wellbeing.

Can you really enlarge your penis?

You can probably picture those spam emails about penis enlargement. There are a number of treatments marketed to increase penis size, including traction devices, injectables and vacuum devices.

However, the evidence for these therapies is weak and there are often complications. Some people opt for surgery, but satisfaction rates are low.

Most people seeking these therapies actually have a normal penis size prior to treatment. Counselling is always recommended and is a very effective treatment for dissatisfaction, and can result in people deciding not to undergo any further treatment.

Unfortunately, distress around penis size is common. Don’t underestimate the effect it can have on your wellbeing – if you’re concerned, it’s always a good idea to speak to your doctor to find out what is right for you.