When Do Penises Start and Stop Growing?

Penis growth begins during puberty, typically at the average age of 12 in males, and stops at the end of puberty, typically around the ages of 18-21. 

Penis growth, shape, and size vary greatly, and there is no “normal” size. As long as there is no problem with standard functions such as urination or sexual intercourse, there is no need to be concerned about size. 

However, you may still wonder when penises start growing, when they stop, their average size, and if there are safe ways to increase size. 

When Penises Start and Stop Growing

Penis growth begins during puberty, the time when a person starts to sexually mature. For those assigned male at birth, puberty typically begins between the ages of 9 and 14. However, this is just a range, and puberty does sometimes occur outside these ages.

For males, the hormone testosterone increases during puberty, which causes multiple physical changes, including growth height, changes in body composition, and the appearance of secondary sex characteristics, like the growth of facial and pubic hair. 

Typically, testicle growth is the first sign of puberty. It starts with changes in the scrotum (the sac that contains the testes). This bag of skin darkens, enlarges, and drops. The skin also thins and develops tiny bumps or hair follicles. Often, one testicle is lower than the other. This is completely normal and common.

About a year after testicle growth begins, the penis starts growing. It grows in length first and then in width (girth). Similar to height, this growth happens in spurts. It’s rapid for a few weeks, then slows down before growing again.

Penis growth continues to the end of puberty. It lasts about five years and typically ends between the ages of 18-21. 

Other physical changes that occur during puberty include:

• Pubic hair
• Hair on the face, legs, arms, underarms, and then the chest 
• Voice changes (after growth spurt)
• Acne (for some)
• Increased muscle mass
• Growth in stature (height)
• Erections and ejaculation are more common
• Erections can be random and inconvenient
• Nocturnal emissions (“wet dreams”)

What's the Average Penis Size? 

Just as there is no “normal” age of puberty, there is no “normal” penis size. Penis size is affected by your genetics and your hormones. The averages and ranges vary among different populations.  The following average sizes are from a systematic review of scientific studies:

Average penis length:

• Flaccid: 3.6 inches
• Stretched: 5.2 inches
• Erect: 5.1 inches

 Average penis circumference (girth):

•  Flaccid: 3.6 inches 
• Erect: 4.5 inches

To measure penis length, use a measuring tape and begin at the base. The shaft begins at the pubic bone, so gently press in until you feel the bone. From there, stretch the measuring tape to the tip.

To measure girth (circumference or around), gently wrap the measuring tape around the largest area of the shaft. Record the number that meets the end of the measuring tape.

Can You Increase Your Penis Size? 

There are medical and surgical interventions that may increase penis size. But, the scientific evidence is sparse. This makes it difficult for reputable organizations to provide guidelines or recommendations. 

These interventions require expert medical or surgical care. There are no over-the-counter pills, supplements, creams, weights, or exercises with enough scientific evidence to verify they can actually increase penis size. 

While a vacuum pump helps those with erectile dysfunction achieve an erection, it does not permanently increase size. 

Some people use traction devices or an extender. This requires stretching the penis for multiple hours a day for several months. It might work if you maintain a strict schedule. But, results are not guaranteed, and it can cause pain and numbness.

Examples of procedures or surgeries performed by a highly-trained and skilled urologist include:

• Autologous fat injection: An injection of a person’s own fat.
• Fillers: Four to six injections of fillers such as hyaluronic acid (HA)
• Grafting procedures: Utilizes artificial or autologous (self) skin or fat 
• Biodegradable scaffolds: Injection of re-absorbable material that promotes new tissue growth 
• Penuma: This surgical silicone implant works about 57% of the time.

It’s important to note that these can be delicate and risky procedures. Only a high-trained urologist should perform them. Attempting any type of injection yourself is not safe.

One research study notes that inmates were self-injecting petroleum jelly into their penis. This can produce dangerous consequences, including painful sex, infection, skin necrosis (skin death), and loss of a part or all of your penis.

When considering a medical or surgical option, it’s worth the time to do plenty of research beforehand. Find a skilled urologist and double-check their credentials. Some people attempt these procedures on the black market, and checking credentials helps ensure your provider is qualified.

Complications from these procedures can be devastating,  especially if performed by someone who is not qualified. They can include deformity, sexual dysfunction, infection, shortening, erectile dysfunction, and death. 

Also, those with average size penis who request surgical techniques may require psychological counseling before approval. This is because the surgery is invasive and comes with the risk of complications. 

If you don’t want a medical procedure but are looking for simple tips and tricks to make your penis look larger, the following may help:

• Decrease or remove pubic hair: Pubic hair can cover the penis, making it look smaller. You can shave or look into other hair removal techniques, such as laser therapy.
• Stand up straighter: Poor posture can make your stomach stick out. Having a better posture can change the perception of how far your penis sticks out.
• Lose weight: A large abdomen (belly) can cover or hide the penis, making it look smaller. 

Does Size Matter? 

The bottom line is your penis is healthy if you don’t have issues with urination, sexual intercourse, or reproduction. If you were diagnosed with micropenis, or your penis size causes problems with function, consult a urologist.

Penis size does not indicate how attractive your partner finds you, how well you perform sexually, or how you provide pleasure. It’s also not a sign of your testosterone levels, masculinity, or reproduction ability.

Your height and the size of your hands or feet do not indicate penis size. These ideas often come from outdated cultural perceptions. 

Many men overestimate the average penis size and how theirs compares. This, along with common misconceptions cause men with an average-size penis to be self-conscious.

Research shows that over 50% of men are not satisfied with the size of their penis, while 85% of their partners are satisfied.

When mild self-consciousness turns into anxiety, it can become a mental health problem. Those with small penis anxiety have a preoccupation with penis size. They think about it for at least an hour a day and frequently check it, causing significant distress. This can turn into penile dysmorphic disorder (PDD).

Dysmorphia is a mental health condition where someone spends a lot of time worrying about perceived flaws in their appearance. They often misjudge their body features. PDD can lead to shame, decreased sexual satisfaction, isolation, psychiatric hospitalizations, and suicide. 

A Quick Review

Penis growth begins and ends with puberty. Puberty typically begins at between the ages of 9 and 14 for those assigned male at birth. Puberty and penis growth usually end about five years later. 

Many men overestimate the average size penis and how theirs compares. Studies show the average size of a flaccid penis is 3.6 inches in length. The average size of an erect penis is 5.1 inches in length. 

Please note that these are just averages, and there is no “normal” size. As long as the size of your penis does not affect your ability to pee, have sex, or reproduce, size does not matter.