Parents often wonder how tall their child will be. Use our calculator to find out. We use the the Khamis-Roche Method (or simply the Khamis Method) to predict height.

What is the Khamis calculator?

According to Dr. Alex Roche, adult height can be predicted using a simple mathematical equation using parent height, current child height, and current child weight.

History of the Khamis Calculator

Dr. Roche worked with researchers on the Fels Longitudinal Study collecting information for personal study and contracted research. The focus of the study was to find predictors that could give some insight into growth rates, final height and final weight in adulthood. After years of research, four factors that contributed to growth were revealed:

• current height
• current weight
• mid-parent height
• skeletal age

With these four indicators, researchers were able to predict, within reason, the height a child would achieve in adulthood. Skeletal age required x-raying the wrist and hand, so this predictor was left out of the final Khamis Calculator. 

(Another method used to calculate height is the gray method. Try this one, too!)

The mathematical equation behind the Khamis Calculator started out simply as double the child’s stature at age two. When this method proved unreliable, especially for girls, Roche refined the equation based on the results of the Fels Longitudinal study. The new linear equations were more accurate:

• Males: 22.7 plus 1.37 times height at 2 years
• Females: 25.0 plus 1.17 times height at 2 years

Additional research led to more fine-tuning and the additional of a child’s current weight to the Khamis Calculator.

Limitations to the Khamis Calculator

The Fels Longitudinal Study, which is the research on which the mathematical equations were based, was primarily a Caucasian study. Since the study lacked participation from other races, the Khamis calculator equations are based solely on Caucasian children born to two Caucasian parents.