While there is no guaranteed method for predicting a child's future height, a few simple formulas provide a reasonable approximation for the majority of children, according to Mayo Clinic. Final adult height depends on three factors: genetics, chronic illness and nutrition, explains WebMD.
A common method for predicting a child's future height is to add the child's parents' heights, in centimeters or inches. Add 5 inches (or 13 centimeters) for boys, or subtract 5 inches (or 13 centimeters) for girls. Finally, divide the sum in half. The adult height of the majority of children falls within a 4-inch range of the answer, notes Mayo Clinic.