Adult Head Circumference Chart

After looking through baby head circumference charts, I wanted to find a comparable adult head circumference chart to compare my head size to the normal distribution. Neither the U.S. Centers For Disease Control and Prevention nor the World Health Organization have adult growth charts. The only available resource is a 1992 academic journal article published in the Archives of Disease in Childhood:

Two different charts are presented on the second page of the article [page 1287 by journal numbering]. The top chart is used for adult males and the bottom chart is used for adult females. Both charts were created using a process similar to that used to create baby growth charts.

The authors measured the height and head circumference of 354 adults in two different dental clinics in Britain. All adults were white volunteers at a median age of 40 years old (with range of 17 years to 83 years). The researchers eliminated anyone who had conditions which might have affected cranial anatomy. Three different researchers performed that actual head measurements with small imprecision among them. The authors note that in a subsample of 20 patients, the standard deviation of measurement error between observers was 0.133 cm.

Turkish Article

I was able to find one more recent adult head circumference chart from a small journal produced by a hospital in Turkey. In the full-text of the Turkish article [] the authors present adult head circumference charts for men and women.

Unfortunately, either there is an error in the Turkish study or the results are not generalizable beyond Turkey. In figure 4 on the third page of the article [page 263 by the journal numbering system], the authors have an adult male head circumference chart by height. My head circumference, 23 in (58.42cm) is not even listed on the chart and flies way over the unmarked top line which I assume is the 95th percentile.

My head circumference is too large to be found on figure 3 [adult male head circumference by weight] as well.

I (very quickly) checked to see if my head was abnormally enormous. Since I know that I wear a size 7 1/4 hat, I verified that my head circumference is accurate given my hat size:

Fitted Cap Hat Sizes

My head circumference correlates nicely with my hat size. In addition, some hat styles are available up to 8 which correspond with a head circumference of 25 in.

Either something is wrong with the data used in the Turkish study or the population of the hospital in Turkey have incredibly small head circumferences compared to the average American who buys hats.

My Personal Conclusion
The 1992 academic article in the Archives of Disease in Childhood provides the best available data on the normal range of adult head circumferences. However, there are severe limitations on that article. The study was based exclusively on health, white, volunteers in two specific British dental clinics and was published 20 years ago.

In my opinion, the range of hat sizes (and corresponding head circumference measurements) sold by commercial businesses provides a better gauge for an adult’s relative head size compared to the population. Given my hat size is 7 1/4, I would estimate my head circumference is around the 60th percentile and likely to be just a little larger than expected for my height
Bushby, Cole, Matthews, and Goodship (1992), Centiles for adult head circumference, Archives of Disease in Childhood
Ormeci, Gurbuz, Ayata, and Cetin (1997), Adult head circumferences and centiles, Journal of Turgut Özal Medical Center