Height Calculator

Use this Children's Height Predictor to estimate a Child's Adult Height with two common calculation methods.

About This Height Calculator

This Height Calculator estimates a child's expected adult height using two methods: the Khamis-Roche Method and the Mid-Parental Height Method. The first method uses a linear regression analysis based on the child's age, height, weight, and parental heights. The second method estimates adult height from the parents' heights alone.

Khamis-Roche Method¹

The Khamis-Roche Method is a linear regression analysis method designed to estimate a child's adult height without using skeletal age. In this calculator, age- and sex-specific coefficients are used.

Formula:

Predicted Adult Height (inches) = b0 + (b1 × Child Height in inches) + (b2 × Child Weight in pounds) + (b3 × Mid-Parental Height in inches)

Where:

• b0, b1, b2, b3 = age- and sex-specific regression coefficients
• Mid-Parental Height (inches) = (Father's Height + Mother's Height) ÷ 2

Example:

For a 5-year-old boy with:

• Child's height = 105 cm = 41.34 in
• Child's weight = 20 kg = 44.09 lb
• Mother's height = 170 cm = 66.93 in
• Father's height = 180 cm = 70.87 in

Mid-Parental Height = (70.87 + 66.93) ÷ 2 = 68.90 in

Using the 5.0-year-old male coefficients in this calculator:

Predicted Adult Height = -11.0213 + (1.10674 × 41.34) + (-0.064778 × 44.09) + (0.53919 × 68.90)

Predicted Adult Height ≈ 69.01 in ≈ 175.29 cm

Mid-Parental Height Method

The Mid-Parental Height Method estimates adult height using the parents' heights only. It is simpler than the Khamis-Roche Method and is often used for a quick height prediction.

Formula for boys:

Predicted Adult Height = ((Father's Height + Mother's Height) + 12.7 cm) ÷ 2

or in inches: Predicted Adult Height = ((Father's Height + Mother's Height) + 5 in) ÷ 2

Formula for girls:

Predicted Adult Height = ((Father's Height + Mother's Height) - 12.7 cm) ÷ 2

or in inches: Predicted Adult Height = ((Father's Height + Mother's Height) - 5 in) ÷ 2

Example:

• Father's height = 180 cm
• Mother's height = 170 cm

For a boy:

((180 + 170) + 12.7) ÷ 2 = 181.35 cm

For a girl:

((180 + 170) - 12.7) ÷ 2 = 168.65 cm

How to Use the Calculator

• Choose Metric Units or US Units.
• Enter the child's age, gender, height, and weight for the Khamis-Roche calculation.
• Enter the mother's and father's heights.
• To use only the parent-based formula, check Based on the Parents' Heights Only.
• Click Calculate to see the result and comparison chart.

Important Notes

• The Khamis-Roche Method is generally used for children from about 4.0 to 17.5 years.
• The published standard error is approximately 2.1 inches (5.33 cm) for boys and 1.675 inches (4.25 cm) for girls. In practical terms, this means that about 90% of children are expected to reach an adult height within this prediction range.
• Results are estimates, not guarantees.
• Growth can be affected by genetics, nutrition, health conditions, puberty timing, sleep, and physical activity.

Disclaimer

This Height Calculator is for educational and informational purposes only. It does not provide medical advice, diagnosis, or treatment. A predicted result should not be considered a guarantee of final adult height. For concerns about a child's growth pattern, please consult a pediatrician or other qualified healthcare professional.

Reference

For general child growth information, you can review these government sources:

• CDC Growth Charts
• MedlinePlus: Child Growth and Development
• NICHD Growth Information

1. Khamis HJ, Roche AF, "Predicting adult stature without using skeletal age: the Khamis-Roche method", Pediatrics, 1994 Oct;94(4 Pt 1):504-7.