how big is an average newborn head
The bones in your babyâs skull are still growing together, and the skull is growing faster during the first four months than at any other time in her life. The average newbornâs head circumference measures about 13 3â4 inches (35 cm), growing to about 15 inches (38 cm) by one month. Because boys tend to be slightly larger than girls, their heads are larger, though the average difference is less than 1â2 inch (1 cm).