circumference reference

To find the circumference of your head use a measuring tape (using the inches side) and start at the top of your head going around your ears, making sure to include the nape of the neck, and back around until it meets again. 

To find front to nape start at the hairline with the measuring tape (using the inches side) and bring it to the nape of the neck.

To find nape of neck measurement start from the left side of the nape with the measuring tape (using the inches side) and bring it across to the right side.