Men's Health

Average Testicle Size - What's Normal?

Fact Checked

Does the size of your testicles matter? Find out all the facts you need to know about the average size of testicles.

Last Updated: 09/13/2021

Written by

James Lang

Medically Reviewed by

Dr. Paul Thompson

Confucius once wrote: “One hundred women are not worth a single testicle.”

Even though this saying is exaggerated and sounds like prejudice, testes play a very important role in the reproductive system. 

Testicles are the male reproductive gland. Their function is to produce sperm and androgens.

Androgen refers to any natural or synthetic hormone that is responsible for the growth and maintenance of male characteristics. The testicles secrete mainly testosterone, which is the primary male sex hormone. 

Testicles (AKA testes, jewels, balls, nuts, bollocks, etc.) are two oval-shaped organs, located behind and below the penis in a sac of thin skin, called the scrotum

Fun fact: “Testis” (plural testes) is the Latin word for “witness”. It is said that testicles witness male virility and the act of love. 

What is the average testicle size? 

Testicles size varies. Most men have two testes and each typically measures around 1.6 x 1.2 x 0.8 inches (4 x 3 x 2 cm). 

The average weight of testis in adult men is around 0.5-0.7 ounces (15-20 grams) per testis.

It is completely normal for one of your testes to be smaller than the other. The difference is about the size of half a teaspoon. Usually, the left testicle tends to be smaller than the right one. 

Also, one of your testicles might hang lower than the other within the scrotum. This is also normal. 

Key takeaway: The average testicle size varies and both testes differ in size and position. 

Does size matter?

The size of your testicles does not affect your health directly. However, some studies in animals and humans suggest that testes’ size impacts the amount of sperm production and testosterone levels.  

A 2011 study in Soay sheep found that larger testicles were related to higher testosterone levels and the production of more sperm. This study also suggested that the testes’ size predicted mate-seeking behavior and male aggression. 

A 2012 study examined 312 men with sexual dysfunction. The researchers found a relationship between testicle volume and levels of male hormones. Men with smaller balls tend to have weaker testosterone production. 

A study published in 2014 examined 236 participants over a period of one year. The participants included 136 men who had been diagnosed with male infertility, as well as 100 healthy males who served as controls. The study found that smaller testes are associated with lower sperm density and production, and lower testosterone levels. 

Even though it might seem that having smaller nuts has only downsides, there are also studies suggesting the opposite

A 2013 study recruited 70 biological fathers of young children. Fathers were between 21 to 55 years old. The findings suggest that fathers with smaller testicular volumes experienced higher nurturing-related brain activity when seeing pictures of their children.

Another study that was also published in 2013, examined 2,809 men consulting for sexual dysfunction. The findings revealed that larger testis size is one of the risk factors for heart disease. 

Key takeaway: The volume of your jewels does not impact your overall health unless you are diagnosed with a certain condition (keep reading to find out more about that!). There are pros and cons to both large and small testes. 

Testicle Growth

At birth, the average testicle size is one cubic centimeter. It only starts growing at about 8 years old. 

The testes continue to grow during puberty until they reach their adult size, which usually happens when the teenager’s pubic hair appears.  

A 2018 study reveals that the average age when the penis and testicles stop growing is 15.6 years old. However, everybody experiences growth spurts differently and there are no fixed rules. 

Some people might go through a growth sprout as early as 12 years old, while for others this can happen much later in their senior high school year. 

3 conditions that cause small testicles

Testes size varies from person to person. It is crucial to realize that size differences may or may not be related to a diagnosable issue. These differences could be meaningless when it comes to the healthy function of your genital organs. 

However, three conditions might result in having smaller testicles. 

Male Hypogonadism

Hypogonadism occurs when the body is unable to produce enough testosterone, limiting the normal development of masculinity traits, such as testicle growth. 

The testicles may not respond to the brain's signal to produce more testosterone and sperm if they have a testicular disease.

There are two types of hypogonadism

  • Primary hypogonadism - in this condition, the testicles may not respond to the brain's signal to produce more testosterone and sperm, due to a testicular disease. It is either inborn or caused by factors, including infection, anabolic steroid overuse, or testicular torsion (a spermatic cord twisting within the testicle). 

  • Secondary hypogonadism - this condition is not caused by a problem in the testicles. It occurs when the pituitary gland fails to generate enough luteinizing hormone, which signals the testicles to produce testosterone. 

Hypogonadism must be treated if it affects fertility. The treatment methods include taking oral medications, hormone injections, and testosterone replacement therapy. 

Undescended Testicles

In this condition, one or both testicles fail to move down to the scrotum prior birth. 

In some cases, the condition can be resolved by itself during the first few months. If it doesn’t, it needs to be treated surgically. 

Males with undescended testicles might have smaller than the average size testicles as adults. 


The scrotum contains a network of veins and nerves that ensure blood flow to the testicles. 

Varicocele is an enlargement of the veins, usually because of issues with the valves that control the blood flow. This condition can cause the testicles to shrink or soften. 

This condition might not need to be treated unless it causes infertility or it worsens the health of your testicles. Varicocele can be cured by surgery. 

Key takeaway: Testicle growth is an individual process and testes size varies from person to person. As long as you are not diagnosed with an underlying condition, it is most likely that the size of your balls is normal and it does not impact your health. 

How to keep your testicles healthy

Taking care of yourself and your body is essential for your overall well-being 

Living a healthy lifestyle and paying attention to changes decreases the risk of numerous diseases and conditions. Here are a couple of things you can start doing to maintain the health of your testicles. 

Perform a testicular self-exam (TSE) every month. 

The test takes less than a minute. Hold your balls in the palm of one hand and gently roll your testicles between your thumb and fingers of the other hand. By feeling their shape, size, and hardness, you will be able to tell whether some abnormalities occur. Your nuts should be firm and oval-shaped. 

The perfect time for self-examination is after a warm shower when your balls are loose. 

Maintain a nutritious-rich diet. 

A research study published in 2020 examined 2935 men and divided them into four groups that had to follow a different dietary pattern. The findings support the researcher’s hypothesis that men who adhere to a healthy nutrition plan have better testicular health and semen quality. 

A healthy nutrition plan includes whole, minimally processed foods, such as fruits, vegetables, meat, eggs, whole grains, seeds, nuts, and high-quality dairy products. 

It is also important to note that excessive alcohol intake should be avoided. Studies reveal that ethanol (the chemical used to produce alcohol), can have a harmful effect on the male reproductive tract. 

Get enough sleep. 

Sleep allows your body and mind to recharge and recover. It is crucial for maintaining low stress levels, remaining healthy and productive, and functioning properly. 

Sleep is also important for your testes and fertility. According to research, longer sleep is associated with larger testicle volume and higher male reproductive potential. 

Key takeaway: In order to maintain healthy testicles, do a testicular self-exam every month. Keep your diet healthy and make sure you get enough sleep. 

Frequently Asked Questions

There might be a problem with my testicles. When should I see a doctor? 

You should see a doctor if anything about your testicle health bothers you. Common reasons to seek medical advice include: 

  • you feel any bumps or lumps that weren't there before

  • you struggle to get your partner pregnant

  • you have low libido

  • you experience a feeling of heaviness in the scrotum, or trauma.  

  • you feel testicular pain or swelling

  • you believe you have inflammation of the testicles.

Can I have a normal life with one testicle? 

If you have one testicle, you can still have a normal, happy, and active life. One testis is enough to produce testosterone and be able to get an erection and ejaculate. 

You can also have children, as long as you don’t have a condition that affects your fertility. 

Why do my testicles shrink when it’s cold?

Testicle temperature plays an important role in sperm production. The scrotum changes its size, to preserve heat and keep the testes at the right temperature. 

Do women care about testicle size? 

Your jewels are not the first thing a woman notices when you’re having sex. Most women don’t have any preferences when it comes to balls. 

Discussions on Quora and Reddit with tens of comments from females, display that the large majority of women do not care about the size of your balls. 

What is the risk of testicular cancer? 

Testicular cancer can occur at any age but it is most common among teens and younger men between the ages of 15 to 35. Testicular cancer is relatively rare and it affects about 1 of every 250 men.  Even though it is usually treated successfully, an early diagnosis is crucial. 

What causes testicular atrophy? 

Certain medical conditions are the most common reason for testicular atrophy (shrinkage of the testicles). Conditions and diseases that can cause testicular atrophy include syphilis, mumps, viral infections, testicular tuberculosis, etc.