Understanding How Large is the Average Male Head

September 30, 2025 •

4 min read

According to several studies, the average adult male head circumference is approximately 57 to 58 centimeters (or 22.5 inches). This figure, however, represents a wide spectrum of normal variation, and it's important to understand the broader context of what is considered a typical and healthy head size.

Quick Summary

The average male head circumference ranges from 57 to 58 cm, though this figure varies significantly based on genetics, height, and body size. Measurements outside the typical range may sometimes signal an underlying health issue, while the long-held belief linking head size to intelligence is largely a myth.

Key Points

Average Circumference: The typical adult male head circumference ranges from 57 to 58 cm (22.5 to 23 inches), a metric used often for hat sizing.
Normal Variation is Broad: There is a wide range of normal head sizes, with average serving as a midpoint rather than a strict standard for health or ability.
Genetics are a Key Factor: Head size is largely determined by genetics, with some families having a natural tendency for larger or smaller heads.
Head Size and Intelligence are Unrelated: The idea that a larger head implies higher intelligence is a myth, debunked by modern science. Any correlations are weak and not indicative of a causal link.
Abnormal Size Can Indicate Health Issues: Unusually large (macrocephaly) or small (microcephaly) heads, particularly when accompanied by other symptoms, may indicate underlying medical conditions and should be evaluated by a healthcare professional.
Measurement is Simple: Accurate head circumference measurement can be done at home with a flexible tape measure, positioning it about half an inch above the eyebrows and ears.

What is the average male head circumference?

Research indicates a consistent range for the average adult male head circumference, although slight variations exist between different studies and populations. A study cited by Wikipedia and other sources suggests the average male head circumference is approximately 57 cm (22.5 inches) in the United States and 57.2 cm in the United Kingdom. Some hat manufacturers also reference an average size around 23.25 inches. These figures highlight that what is 'average' is not a single, fixed number but rather a range within a statistically normal distribution. For adults, head size measurements are typically stable, with growth and development primarily occurring during infancy and childhood.

The importance of percentile charts

Just because a person's head circumference is not exactly at the average doesn't mean it is abnormal. Medical professionals use percentile charts, similar to those used for infants and children, to assess head size relative to a person's age and sex. A head size is generally considered unusually large (macrocephaly) or unusually small (microcephaly) only if it is more than two standard deviations above or below the mean. A familial tendency towards larger heads (benign familial macrocephaly) is a common cause of a large head that is not a cause for medical concern.

How to accurately measure your head

For those interested in finding their own head circumference, whether for hat sizing or personal curiosity, the process is straightforward and can be done at home. Here are the steps:

Gather your tools: You will need a flexible measuring tape, like a tailor's tape, or a piece of string and a ruler.
Position the tape: Wrap the tape measure around your head, placing it where a hat would typically sit. This is usually about a half-inch above your eyebrows, just above your ears, and over the most prominent part of the back of your head.
Secure the fit: Ensure the tape is snug but not uncomfortably tight. It should be level and lie flat against your head.
Read the measurement: Record the measurement in either inches or centimeters. If you are using a string, mark the point where it overlaps and then measure that length with a ruler.
Take multiple measurements: To ensure accuracy, measure your head a couple of times. If you find your measurement falls between two hat sizes, most experts recommend choosing the larger size for a more comfortable fit.

Factors that influence head size

While average head circumference is a useful reference, several factors contribute to an individual's head size, explaining the natural variation found within the population.

Genetics: Inherited traits are a primary determinant of head size. Familial macrocephaly, where a larger head is a common family trait without any underlying medical issues, is a prime example.
Body size and height: A larger overall body frame and greater height are often correlated with a larger head circumference, as confirmed by studies analyzing anthropometric data.
Developmental and environmental factors: In infancy and childhood, factors like nutrition and overall health play a role in head growth. However, adult head size is stable and not affected by these factors later in life.

When to be concerned about head size

For the vast majority of people, head size is perfectly normal and not a cause for concern. However, in some cases, an unusually large or small head can be a symptom of an underlying medical condition. These issues are most closely monitored during infancy and childhood, but adults can also be diagnosed with conditions like macrocephaly or microcephaly.

Macrocephaly: An abnormally large head circumference, defined as more than two standard deviations above the average, may be caused by benign familial traits or by more serious conditions such as hydrocephalus (fluid buildup in the brain), brain tumors, or other intracranial issues.
Microcephaly: A head circumference more than two standard deviations below the average is known as microcephaly. In adults, this is often a congenital condition resulting from abnormal brain development during pregnancy due to genetic or environmental factors.

If you notice a sudden, rapid change in head size or experience symptoms like severe headaches, vision problems, or balance issues, it is essential to consult a healthcare provider.

Debunking the head size-intelligence myth

The historical and pseudoscientific belief that a larger head or brain equates to higher intelligence has been repeatedly debunked. Early craniometry, which sought to measure skulls to rank human groups, was based on flawed methodology and biased conclusions. While modern studies using MRI have found a weak correlation (r = 0.40) between brain size and IQ, this does not imply that a larger head makes you smarter. A systematic review found a positive association between larger head circumferences in the general population and intelligence, but noted that this association was non-linear and not a simple 'bigger is better' scenario. The most significant takeaway is that the size of one's head is not a reliable indicator of intelligence, and what matters is how you utilize your cognitive abilities.

Male vs. Female Average Head Circumference

To provide a clearer context for male head size, here is a comparison with typical female measurements from various sources.


Characteristic	Average Male Head Circumference	Average Female Head Circumference
Measurement (cm)	~57 cm to 58 cm	~55 cm to 57 cm
Measurement (inches)	~22.5 inches	~21.75 inches
Common Hat Size	Large (7 ⅜)	Medium (7 ¼)

Conclusion

The average male head circumference is approximately 57 to 58 centimeters, but this figure is a reference point within a natural spectrum of variation. Influenced by genetics, overall body size, and developmental factors, an individual's head size is not a metric for intellectual capacity. While significant deviations from the norm can sometimes indicate a health issue, most cases of unusually large heads are benign and familial. Understanding these factors provides a more informed perspective on this common biological metric, distancing it from outdated and discredited beliefs about intelligence and human worth. For further reading on developmental biology, authoritative sources like the NIH provide extensive resources (see citation below).

Authoritative Link: The NIH website has information on conditions like macrocephaly and the role of genetics.

Frequently Asked Questions

The average adult male head circumference is approximately 22.5 inches, though some data points from the US and hat industry suggest a slightly higher figure, like 23.25 inches.

No, a larger head does not reliably correlate with higher intelligence. Scientific studies have shown only a weak correlation between brain volume and IQ, and head size is not a direct measure of intellect.

Use a flexible measuring tape and wrap it around your head, placing it just above your eyebrows and ears. Ensure it is snug but not tight. Record the measurement where the tape overlaps.

A head is generally considered large if its circumference is more than two standard deviations above the average for age and sex, a condition known as macrocephaly. For adults, head sizes over 23.5 inches are often considered larger than average.

Yes, genetics are a common cause of larger-than-average heads. A condition called benign familial macrocephaly is an inherited trait where a family has a tendency toward larger head sizes without any associated health problems.

The human head, like the rest of the body, completes most of its growth during childhood and adolescence. Head circumference typically stabilizes in adulthood, generally by the late teens or early twenties.

Yes, on average, adult males tend to have a slightly larger head circumference than adult females. The average female head size is typically around 55 to 57 cm (21.75 inches), compared to the male average of 57 to 58 cm.