# Child Height Calculator

Predict your child's adult height using the mid-parental height method. Calculate estimated adult height based on both parents' heights with a confidence.

## What this calculates

Curious about how tall your child will be as an adult? The mid-parental height method, developed by Dr. J.M. Tanner, uses both parents' heights to predict a child's adult stature. Enter the parents' heights below to get an estimated adult height with a range.

## Inputs

- **Child's Gender** — options: Boy, Girl
- **Father's Height** (cm) — min 140, max 220
- **Mother's Height** (cm) — min 130, max 210

## Outputs

- **Predicted Adult Height** — formatted as text — Estimated adult height using mid-parental height method
- **Predicted Range** — formatted as text — Height range within which most children fall (plus/minus 10 cm)
- **Mid-Parental Height** (cm) — Average of parents' heights adjusted for child's sex

## Details

The mid-parental height method is the most widely used clinical tool for predicting a child's adult height. For boys, the formula averages the parents' heights and adds 6.5 cm (2.5 inches) to account for the average height difference between men and women. For girls, 6.5 cm is subtracted. The result has a standard deviation of about 5 cm, meaning most children (roughly 95%) will fall within plus or minus 10 cm of the prediction.

Genetics account for approximately 60-80% of adult height, making parental height a strong predictor. However, environmental factors including nutrition, health during childhood, hormonal conditions, and overall well-being also play significant roles. Children who experience chronic malnutrition, severe illness, or hormonal imbalances may not reach their genetic height potential.

This prediction is most reliable when both parents are of average height and the child has no underlying growth disorders. For children whose height percentile is significantly different from their mid-parental height prediction, a pediatric endocrinologist may evaluate bone age and growth hormone levels to provide a more accurate prognosis.

## Frequently Asked Questions

**Q: How accurate is the mid-parental height prediction?**

A: The mid-parental height method predicts adult height within plus or minus 10 cm (4 inches) for approximately 95% of children. It is most accurate when both parents are close to average height and the child has no growth disorders. The prediction does not account for nutritional factors, growth hormone levels, or puberty timing, all of which can significantly affect final height. Bone age X-ray analysis provides a more accurate prediction.

**Q: At what age does a child reach their adult height?**

A: Girls typically reach their adult height by age 14-16, about 2 years after their first menstrual period. Boys usually continue growing until age 16-18, with some gaining additional height until age 20. Growth plate closure, which can be assessed by a bone age X-ray, determines when growth stops. Early or late puberty can shift these timelines significantly.

**Q: Can nutrition affect my child's adult height?**

A: Yes, nutrition plays a significant role in achieving genetic height potential. Adequate protein, calcium, vitamin D, zinc, and overall caloric intake during childhood and adolescence are essential for optimal growth. Chronic malnutrition can reduce adult height by several centimeters. In well-nourished populations, genetics is the dominant factor, but in populations with nutritional challenges, improved nutrition has been shown to increase average adult height across generations.

**Q: What if my child is much shorter or taller than the prediction?**

A: If your child's height falls significantly outside the predicted mid-parental height range (more than 10 cm above or below), it may warrant evaluation by a pediatrician or pediatric endocrinologist. Conditions like growth hormone deficiency, thyroid disorders, celiac disease, or constitutional growth delay can affect height. Conversely, some children who are taller than expected may have conditions like precocious puberty. Early evaluation allows for timely intervention when needed.

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Source: https://vastcalc.com/calculators/health/child-height-predictor
Category: Health & Fitness
Last updated: 2026-04-21