The ages of Saudi children are recorded and based on the Hegira calend
ar. When charted on the National Center for Health Statistics (NCHS) w
eight and height charts, children will be at a disadvantage since the
Hegira year is shorter than the Gregorian year. In this paper, centile
s for the NCHS reference population are estimated for age in Hegira ye
ars from 2-18 for height and weight for both sexes using mathematical
interpolation. Charts are prepared for use in hospitals and health cen
ters for children whose ages have been reported based on the Hegira ca
lendar.