Child Height Prediction Calculator
Predict adult height from parents' heights.
Results update as you type.
This calculator provides estimates based on population research. Results are not medical advice. Consult a qualified healthcare provider before making health or nutrition decisions.
How it works
A child's adult height is strongly influenced by genetics, and this calculator estimates it from the parents' heights using the mid-parental height method used by pediatricians. You enter the father's and mother's heights and the child's gender, and it returns the predicted adult height and a likely range. The method averages the two parents' heights and adjusts for gender: for a boy it adds 2.5 inches (about 6.5 cm), and for a girl it subtracts 2.5 inches, reflecting the average height difference between adult men and women. Most children end up within roughly 4 inches (about 10 cm) above or below this prediction, which is why the calculator gives a range rather than a single exact number. Genetics account for the majority of height, but nutrition, overall health, sleep, and physical activity during childhood also play important roles, and serious illness can affect growth. This is a rough estimate, not a guarantee — plenty of children fall outside the predicted range for many reasons. Pediatricians track a child's growth over time on percentile charts, which is a more reliable indicator of expected height than a one-time prediction. Use this as a fun, general guide rather than a definitive forecast, and consult a doctor with any concerns about your child's growth. Enter the parents' heights and the child's gender to see the prediction.
Boy = (father + mother + 5) ÷ 2; Girl = (father + mother − 5) ÷ 2 (inches)
The mid-parental height method averages the parents' heights and adds 2.5 inches for a boy or subtracts 2.5 inches for a girl (adding or subtracting 5 before dividing by two). Most children reach within about 4 inches of this prediction.
Source:Mid-parental height method (pediatrics)
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter father's height, mother's height and child's gender.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Predicted adult height updates instantly as you type — no button to press.
Frequently asked questions
How do you predict a child's adult height?
The mid-parental method averages the parents' heights, then adds 2.5 inches for a boy or subtracts 2.5 inches for a girl. For a father of 70 inches and mother of 64, a boy's prediction is about 69.5 inches. Most children end up within about 4 inches of this figure, so the calculator provides a likely range.
How accurate is the mid-parental height method?
It gives a reasonable estimate since genetics strongly influence height, but it is not precise. Most children fall within about 4 inches above or below the prediction, which is why a range is given. Individual results vary widely due to genetics beyond the parents, nutrition, health, and other factors, so treat it as a rough guide, not a guarantee.
What besides genetics affects a child's height?
While genetics set the main potential, nutrition, overall health, adequate sleep, and physical activity during childhood and adolescence all influence how much of that potential is reached. Chronic illness, hormonal conditions, or poor nutrition can limit growth. Good nutrition and healthy habits help a child grow toward their genetic potential.
Why is a range given instead of one number?
Because height prediction is inherently uncertain. The mid-parental figure is an average expectation, but real children vary around it due to the mix of genes they inherit and environmental factors. Most land within about 4 inches on either side, so the range captures where a child is likely to fall better than a single precise-looking number.
Should I worry if my child is outside the range?
Not necessarily — the prediction is a rough estimate, and many healthy children fall outside it. What matters more is that a child grows steadily along their own percentile curve over time, which pediatricians monitor. If you have concerns about your child's growth rate or height, consult a doctor, who can assess it properly rather than relying on a one-time estimate.