How the height prediction works
Children usually grow to a height close to the average of their parents, adjusted for the typical 5-inch (13 cm) difference between adult men and women. This is called mid-parental height, and pediatricians use it as a "target height" when they look at a child's growth chart.
- Boys: (mother's height + father's height + 5 in) ÷ 2
- Girls: (mother's height + father's height − 5 in) ÷ 2
Example: a mother who is 5 ft 4 in (64 in) and a father who is 5 ft 10 in (70 in). A son's target is (64 + 70 + 5) ÷ 2 = 69.5 in, about 5 ft 9½ in. A daughter's is (64 + 70 − 5) ÷ 2 = 64.5 in, about 5 ft 4½ in.
What else affects height?
Genes explain most of the difference in height between people, but not all of it. Good nutrition, enough sleep and overall health during childhood help a child reach their potential. Long-term illness or poor nutrition can reduce growth. The range shown above covers how far most children land from their target.
Average adult height in the US
According to CDC survey data, the average adult man in the United States is about 5 ft 9 in (175 cm) and the average woman about 5 ft 3½ in (161 cm).
Converting heights? The unit converter handles feet, inches and centimeters. Checking a healthy weight for an adult height? Try the BMI calculator.
Last reviewed October 2026.
Frequently asked questions
How is adult height predicted from the parents?
This calculator uses the mid-parental height method (also called target height). For a boy, add the mother's and father's heights, add 5 inches (13 cm) and divide by 2. For a girl, add the two heights, subtract 5 inches (13 cm) and divide by 2.
How accurate is the prediction?
It gives a likely range, not an exact height. About 95% of children end up within roughly 4 inches (10 cm) of their mid-parental height. Nutrition, sleep, health and genetics that skip a generation can all move a child above or below it.
Is there a more accurate method?
Doctors can make closer predictions using a child's current height, growth over time and a bone age X-ray. If you have concerns about how your child is growing, a pediatrician can check their growth on a chart over several visits.
Can my child grow taller than both parents?
Yes. Height is shaped by many genes from both sides of the family, so children can end up taller or shorter than either parent. Better nutrition across generations has also made average heights rise in many countries.
When do children stop growing?
Most girls reach adult height around age 14 to 16, and most boys around 16 to 18, a couple of years after puberty starts. Some young people keep growing a little into their late teens or early twenties.