A child's future height can be estimated by the time she reaches age 2. In Medical Edge, a newspaper published by the Mayo Clinic, Dr. Siobhan Pittock states, "That's because by 2 most children have reached the growth chart percentile they will stay on as they grow." Determining how tall your 2 1/2-year-old child will be in adulthood requires a little math, but by measuring, subtracting and multiplying, you can figure the approximate future height of your toddler.
Measure your child by having him stand with his back against a wall, helping him stand straight and tall with his heels touching the wall. Make a pencil mark on the wall at the top of his head. Allow him to walk away, then measure in inches from the floor to the pencil mark with a measuring tape.
Subtract 1 1/2 inches. According to growth charts published by the Centers for Disease Control, children grow approximately 1 1/2 inches from age 2 to age 2 1/2. The number you have now is the approximate height of your child at 2 years of age.
Double this number. This is the height your child will likely grow to be as an adult. Boys may be a little taller than this height, and girls are generally a little shorter.
If you have past growth charts from your doctor showing your child's height at age 2, simply double that number to find a more accurate result. This activity provides you with only an estimation. If you have any questions or concerns about the growth of your child, ask your pediatrician.