How tall your child will be as an adult?
While no test is 100 percent accurate, once your child is 2 years old, his doctor can begin to predict his adult height using the following methods:
Also known as the Bayley-Pinneau scaling law, a doctor uses an X-ray of a child’s hand and wrist to determine skeletal age (also called bone age). By comparing this information to historical data, doctors can make fairly accurate predictions of the height of your little one when he becomes an adult.
In the mid-1990s, a doctor and a statistician teamed up to find a simpler solution than X-rays. They developed the Khamis-Roche Method, a mathematical formula that you can begin to use once a child is 4 years old.
Simply plug in a child’s current weight, height, age and parents’ adult heights to predict your little one’s eventual adult stature. A calculator does the rest — no radiation required. While it may not work for exceptionally tall kids, it is the most accurate predictor without getting an X-ray.
The mid-parental height method
Most kids grow to about two inches of what’s known as their parents’ “mid-parental height,” which finds the average of parent’s heights using different formulas for boys and girls.
The formula can give you a good idea of your child’s height, though it’s not an exact science. For boys, adult height is calculated by combining both parents’ heights, dividing by two, then adding 2.5 inches. For girls, you’d add Mom’s and Dad’s heights together,divide by two, then subtract 2.5 inches.
While there aren’t studies verifying the accuracy of this popular method, it’s a quick way to give curious parents an idea of what to expect. So much growth happens during the toddler years that kids generally reach half of their adult height within the first two years of life.
Simply doubling your boy’s height at 2 years old and your girl’s height at 18 months (since girls tend to develop faster than boys) gives you a rough guesstimate of your child’s future stature.
Why predict height?
It’s not just a fun tidbit of information. Once you and your doctor know your child’s estimated adult height, you won’t worry so much when the the inevitable growth spurts and plateaus of childhood and adolescence happen.
And if your child is consistently shorter than the trend for her predicted adult height, your doctor can explore whether an undiagnosed illness or nutritional deficit is to blame.