Calculation method
Based on parents' height (mid-parental formula): Boy = (Father + Mother + 13) ÷ 2, Girl = (Father + Mother − 13) ÷ 2, with a predicted range of ±5 cm. The current-height method compares the child's age and current height with the average for the same age to estimate a growth percentile, then predicts the final height (range ±4 cm).