Height Calculator

Two methods

Khamis-Roche method (ages 4 to 17½): a regression published in Pediatrics in 1994 that combines the child’s current height and weight with the average height of the parents. It does not need an X-ray of the hand (bone age). In the original study 90% of predictions were within about 2.1 inches (5.3 cm) for boys and 1.7 inches (4.3 cm) for girls.

Mid-parental height (any age): the average of the parents’ heights, plus 6.5 cm (2.5 in) for a boy or minus 6.5 cm for a girl. Most children end up within about 8.5 cm (3.3 in) of this target.

Example

A 10-year-old boy who is 4 ft 7 in (55 in) and weighs 70 lb, with a mother of 5 ft 4 in and a father of 5 ft 10 in, is predicted to reach about 5 ft 10.4 in (178.7 cm). He has reached about 78% of his adult height. His mid-parental target is 5 ft 9.6 in.

Limits of any prediction

• The method was developed on white American children; accuracy can differ in other populations.
• Early or late puberty shifts growth in time but changes the final height much less.
• Illness, nutrition and some medicines affect growth. If you are worried about a child’s growth, talk to a pediatrician, who can compare measurements over time on a growth chart.

Frequently asked questions