What is the average infants head circumference for a 5 month and 10 day girl?

See answer . To a very specific question here is a very specific answer: average head circumference of a 5 month 10 days baby girl is 42cm or 16.5 inches. If u need more information or the normal range of head circumferences for any age group then u can look up under: cdc.gov/ growthcharts. .