Mid-Parental Height Calculator

About this calculator

The mid-parental height method is a widely used pediatric estimate of a child's likely adult height, based on the simple observation that height is strongly heritable. The formula averages both parents' heights and applies a fixed adjustment for the child's sex — adding about 6.5 cm for boys and subtracting about 6.5 cm for girls — to account for the average height difference between men and women.

This calculator takes both parents' heights and the child's sex and returns the predicted adult height along with the expected ±8.5 cm range that reflects normal biological variation around the estimate. It's used by pediatricians and pediatric endocrinologists as a rough benchmark when tracking a child's growth curve — a child growing well outside their predicted range can be a signal to investigate growth hormone or other endocrine issues — though it remains an estimate, not a guarantee, since genetics beyond the parents and environmental factors also play a role.