Understanding Children's Height Prediction: The Khamis-Roche Method
Learn how pediatricians and scientists predict how tall your child will be using a combination of genetics and current growth data.
Use the Height Calculator to apply the concepts in this guide to your own measurements.
The Science of Height Prediction
Predicting how tall a child will grow to be as an adult is a common question for parents. While genetics play a massive role, nutrition, sleep, and overall health are also critical factors.
What is the Khamis-Roche Method?
Developed by Dr. Harry Khamis and Dr. Alex Roche in the 1990s, this method is considered the most accurate way to predict a child’s adult height without using an X-ray to determine skeletal age.
It uses four simple data points:
- The child’s gender
- The child’s current age
- The child’s current height and weight
- Both parents’ heights
The margin of error for the Khamis-Roche method is roughly 1.7 inches for boys and 2.1 inches for girls.
How Genetics Play a Role
Genetics account for about 70-80% of a person’s final adult height. This is why our “Parents’ Heights Only” calculator provides a decent baseline. This simpler method, often called the “mid-parental height” formula, calculates the average of the parents’ heights and adds (for boys) or subtracts (for girls) a standard constant.
However, because it doesn’t take into account the child’s actual growth trajectory (like early or late puberty), it is less accurate than the Khamis-Roche method for older children.
Tips for Supporting Healthy Growth
To help your child reach their genetic potential:
- Ensure they get adequate sleep (growth hormones are released during sleep)
- Provide a balanced diet rich in calcium, vitamin D, and protein
- Encourage regular physical activity