Follow these steps

1. Ask the child to sit on a chair. Infants and young children can sit in the assistant’s lap.
2. Remove hair ornaments and hat, if any.
3. With your fingers, feel for a bump in the back of the head and position the tape over the bump.
4. Ask assistant to hold the tape in place over the bump.
5. Wrap the tape tightly around the head making sure to position it over the most prominent part of the forehead (often 1-2 fingers above the eyebrow).
6. Secure the tape using both hands and gently tug on it by moving your left hand to the left and right hand to the right.
7. Read head size measurement and record to the nearest 0.1 cm (e.g. 43.2 cm).