Preemie, Baby, Toddler, Child, Tween. Circumference (in.) 9–12, 14–16, 16–18, 18–20, 20– (cm.) 23–, –, –46, –51, 51– Adult.
Head breadth, 1, The maximum breadth of the head, Static adult human physical characteristics of the head - redrawn.
Average Adult Head Sizes in Australia. According to Wikipedia, one study in the United States shows, the average adult head circumference to be 55cm (21 3⁄4) .
The mean head circumference of a male of average height is above the 97th Relationship between head circumference and height in normal adults and in the .
The national average is estimated to fall between 22 and 23 inches, but there is no current government data on adult head size. Science has.