How predicted height is calculated
The mid-parental height method calculates an average of both parents' heights, then applies a sex-specific correction: +6.5 cm for boys (to account for the sex height difference) and −6.5 cm for girls. This gives the predicted adult height for the child.
A ±10 cm range is applied around the predicted value, reflecting the Tanner-Whitehouse estimate that covers approximately 95% of outcomes for children of those parents. Actual adult height also depends on nutrition, childhood health, sleep quality, and other environmental factors during the growth period.