<P> Different headpieces can also signify status, origin, religious / spiritual beliefs, social grouping, team affiliation, occupation, or fashion choices . </P> <P> While numerous charts detailing head sizes in infants and children exist, most do not measure average head circumference past the age of 21 . Reference charts for adult head circumference also generally feature homogeneous samples and fail to take height and weight into account . </P> <P> One study in the United States estimated the average human head circumference to be 55 centimetres (21 ⁄ in) in females and 57 centimetres (22 ⁄ in) in males . A British study by Newcastle University showed an average size of 55.2 cm for females and 57.2 cm for males with average size varying proportionally with height </P> <P> Macrocephaly can be an indicator of increased risk for some types of cancer in individuals who carry the genetic mutation that causes Cowden syndrome . For adults, this means refers to head sizes greater than 58 centimeters in men or greater than 57 centimeters in women . </P>

What is the average size of a head