Child Height Predictor

Mid-Parental Height Formula

The predicted adult height (target height) is based on both parents’ heights and the child’s sex:

• Boys: (father + mother + 13 cm) ÷ 2, or (father + mother) ÷ 2 + 2.5 in
• Girls: (father + mother − 13 cm) ÷ 2, or (father + mother) ÷ 2 − 2.5 in

Prediction Range

This is a genetic-potential estimate only. Nutrition, sleep, activity and health all affect final height. For any growth concerns, speak to your doctor.

Frequently Asked Questions

How does the mid-parental height method work?

You average the parents’ heights, then add 6.5 cm (about 2.5 inches) for a boy or subtract the same for a girl. In centimetres, add or subtract 13 cm after summing both parents and dividing by two.

How accurate is the prediction?

About 95% of children reach an adult height within ±10 cm (±4 inches) of the mid-parental estimate, which is why a likely range is shown alongside the single value.

What else affects a child’s adult height?

Genetics set most of the potential, but nutrition, sleep, physical activity, overall health and the timing of puberty all influence final height.

Can I check whether my child is on track?

Yes. Your doctor plots height on a growth chart over time. Steady tracking along a percentile curve is more informative than any single prediction.

Does this work for any age?

The mid-parental method predicts final adult height from the parents alone, so it does not depend on the child’s current age. It is a genetic-potential estimate, not a measurement of current growth.