Predicting Your Baby’s Height

Obie Editorial Team

When I was born my dad was 6’4 and my mom was 5’2. Clearly, my dad was taller than the average man, while my mom was shorter than the average woman. They always joked through my infancy that I was either going to be a perfectly normal height or I was going to take on one of their abnormal height characteristics. They didn’t have trouble predicting it for long, though. By third grade, I was at least a head above all of my classmates, and my mother was endlessly frustrated about my inability to find pants long enough in any children’s clothing store. By fifth grade, I was 5’9, and my gargantuan height was still embarrassing. Luckily, by ninth grade all of the boys caught up to me, and now my peers envy my lengthy stance. I’m 5’10 now, so I obviously took on the stature of my dad. I remember as a child the doctors were predicting my height based on a chart that outlined weight and age. Upon further research, I’ve found that height prediction is actually fairly accurate in modern medicine.

In 1994, HJ Khamis developed a measurement system that took each parent’s height into account to determine the height of their child by age eighteen. The results of the system are shockingly accurate, but they only apply to children without any skeletal irregularities. In fact, experts say that environmental factors cannot possibly be accounted for in the study, which is where any inaccuracies might come from. Diet has been known to affect growth, and physical activity such as gymnastics can cause a child to end up shorter than expected as well. In the calculation, 70% of a child’s height is predicted by his or her parents’ height, and 30% is attributed to environmental factors.

When I used a Khamis calculator just now based on the heights of my parents when I was born, the results were 100% accurate. The test determined that I would have been 5’9 by age eighteen, which I most definitely was.

Anything can happen, and there’s no way you can definitely predict your child’s height for certain. However, if there are no problems with his or her growth, the Khamis measurement prediction system is accurate, so it might be fun to try. However, you shouldn’t necessarily go out to buy his or her clothes for the 18th birthday party just yet, for style’s sake.

Source: HJ Khamis et al: Predicting Adult Stature Without Using Skeletal Age: The Khamis-Roche Method. Pediatrics Volume 95 Issue 3 pp. 457 1995