Does Size Matter?

Does size matter? Ah, yes, the age-old question. But don’t worry—we’re not talking about female preferences here. We’re talking about fertility (obviously)!

In 2018, a group of researchers from the University of Utah decided to investigate whether or not a man’s penis size was linked to his fertility levels. The doctors looked at data from 815 men who had visited a clinic looking for reproductive health treatment between 2014 and 2017. On average, guys with fertility issues had penises that were roughly 0.4 inches shorter than men without reproductive problems: infertile men were 4.92 inches in length on average, while fertile guys were around 5.3 inches long.

But wait…does 0.4 inches really matter that much?

When it really comes down to it, no. Infertility is caused by many different genetic symptoms that sometimes are associated with smaller penises. This doesn’t necessarily indicate that people with smaller penises are less likely to conceive a child. This is especially true when considering that sperm are generated in the testicles, not the penis.

Even the study co-author, Dr. Austen Slade, stated, “Men with shorter penises don’t need to worry about their fertility.”

One exception lies in men born with micropenises, caused by a hormonal abnormality in fetal development in which the baby boy does not get enough testosterone. Micropenises are associated with growth hormone deficiencies, which can lead to infertility. They also make it more difficult for a sperm cell to reach the right point in the vagina where it can meet with the egg (though this can be alleviated with some specific sex positions that allow a woman to take control of the position of the penis).

Does ANY size determine fertility?

In 2011, research published in the journal Environmental Health Perspectives explained that penis size is not significant. However, another measurement is: the length measured from the anus to underneath the scrotum, known as the anogenital distance (AGD). Men with a shorter AGD are more likely to have lower sperm counts and are only half as likely to succeed in getting a partner pregnant. However, AGD isn’t just affected by the length of penis, but also by other factors such as overall body size. Lower AGD measurements have also been found in the children of mothers exposed to a group of chemicals called “phthalates,” which are used in everyday products from cosmetics to food packaging to household cleaners.

Dr. Slade’s study from 2018 has many limitations, and men should be warned before heeding any information published about it: testosterone levels in the subjects were not tested (testosterone levels are an important indicator of male reproductive health), and female partners were not tested for their own fertility levels.

“Unsubstantiated research has the potential to increase unnecessary anxiety, which can cause a host of other problems. In today’s world, such anxiety typically leads to unnecessary testing and sometimes unnecessary medical treatment.”

The bottom line is this: if you suspect you have a fertility problem, see your doctor. Improve your lifestyle: limit alcohol consumption, eat a good diet, exercise often, and maintain a normal weight. These are all proven strategies for maximizing your fertility—so stop worrying! Size doesn’t matter.



Bharanidharan, Sadhana. “Can Penis Size Affect Chances Of Conceiving?” Medical Daily, 8 Oct. 2018.

Gander, Kashmira. “Male Fertility Has Been Linked to Penis Size in a Study.” Newsweek, Newsweek, 9 Oct. 2018.

Krans, Brian. “Male Fertility and Penis Size.” Healthline, Healthline Media, 16 Oct. 2018.

Matthews, Melissa. “Guys with Infertility Problems Have Smaller Penises, Says New Study.” Men’s Health, Men’s Health, 25 Feb. 2019.

O’Neill, Maggie. “Can You Get Pregnant If Your Partner Has a Micropenis? Here’s What an Expert Says.” Health, 19 Apr. 2019.

Rochman, Bonnie. “Guys Are Right: Size Matters, When It Comes to Fertility.” Time, Time, 16 Mar. 2011.