There's no proven way to predict a child's adult height. However, several formulas can provide a reasonable guess for child growth. Here's a popular example:

• Add the mother's height and the father's height in either inches or centimeters.
• Add 5 inches (13 centimeters) for boys or subtract 5 inches (13 centimeters) for girls.
• Divide by two.

Another way to estimate a child's adult height is to double a boy's height at age 2 or a girl's height at age 18 months.

Remember, a child's height is largely controlled by genetics. It's also important to note that children grow at different rates. Some children begin their growth phases early, while others are late bloomers.

If you're concerned about your child's growth, talk to his or her doctor. Having the doctor plot your child's growth on a standardized growth chart can determine if your child is following his or her curve, as well as help predict adult height.

Source: https://www.mayoclinic.org/