To measure a baby's head circumference, you can follow these steps:
Find a flexible and non-stretchable measuring tape.
Gently wrap the tape around your baby's head, ensuring it passes just above the eyebrows, over the ears, and around the occipital prominence at the back of the head, near the base of the skull.
Record the head circumference, rounding it to the nearest 0.1 cm for precise measurement.