How Tall Will My Child Be?

Parents often have questions about their children’s growth and how tall they’ll ultimately be as adults. We still have the pencil marks on the wall that track the growing years of our broods, and it’s fun to look back and compare the patterns that show up there.

Several factors help determine adult height, including genetics (how tall are Mom and Dad?), gender, and overall health and nutrition. There are many methods to predict a child’s future height, but one that is simple and popular is to double the height at age 2 years.

Surprised? So were we. But it turns out that this straightforward, at-home formula is just about as accurate as the more complicated diagnostic tools you may have heard about, like comparisons of bone age and chronological age that require x-rays of the hand and wrist to predict future increase in height (the most scientific method).

Another calculation used by pediatricians is based on the fact that most children grow to a height in between that of their mother and father, with a differential thrown in for sex. So add Mom’s height plus Dad’s height, divide by 2, and add 3 inches for a boy, or subtract 3 inches for a girl.

Then there’s a slightly more complicated formula developed by Drs. Harry Khamis and Alex Roche and published in Pediatrics, the official publication of The American Academy of Pediatrics in 1994. These researchers developed a method that eliminated the need for a bone age x-ray. The “Khamis-Roche Method” is fairly accurate (within an inch and a half of actual growth) but is only reliable in children who have no other known medical problems.

Try it, and compare their prediction with yours. Unfortunately, you’ll probably have to wait a few years to know who was right!