Height Calculator
Free Height Calculator to predict your child's adult height using the mid-parental height formula. Get predicted height with confidence range for boys and girls.
About This Calculator
The Height Calculator predicts your child's adult height using the well-established mid-parental height method (also known as the Tanner method). This evidence-based approach estimates adult height based on the average of both parents' heights, adjusted for the child's gender. It is widely used by pediatricians and healthcare providers worldwide as a simple screening tool to assess a child's growth potential.
The calculation uses a straightforward formula: for boys, add 13 cm (5.1 inches) to the average of both parents' heights; for girls, subtract 13 cm (5.1 inches) from the average. The offset of 13 cm represents the average height difference between adult men and women. The result is the predicted adult height with a 95% confidence range of ±8.5 cm (about ±3.3 inches), meaning the actual height is expected to fall within this range for most children.
This calculator is designed for parents, pediatricians, and anyone interested in estimating a child's potential adult height. It supports both metric (cm) and imperial (inches) units and works for male and female children. The mid-parental method is most reliable for children between ages 2 and 8, as growth patterns stabilize after early childhood but before the onset of puberty.
Regional Notes: Average heights vary significantly across countries. In India, the average adult male height is approximately 165 cm (5'5\") and female 152 cm (5'0\"). In the US, average male height is about 175 cm (5'9\") and female 163 cm (5'4\"). In the UK, average male height is approximately 178 cm (5'10\") and female 165 cm (5'5\"). These population averages do not change the formula — the mid-parental method adjusts per individual parents regardless of nationality.
Frequently Asked Questions
What is the mid-parental height formula?
For boys: (Mother's height + Father's height + 13) / 2. For girls: (Mother's height + Father's height - 13) / 2. The result is the predicted adult height with a confidence range of +/-8.5 cm (about 3.3 inches).
How accurate is height prediction?
The mid-parental height method has a 95% confidence interval of +/-8.5 cm. Actual height is influenced by nutrition, sleep, exercise, and overall health during childhood. Genetic factors account for about 60-80% of height variation.
Can nutrition affect my child's height?
Yes, proper nutrition is crucial for reaching genetic height potential. Key factors: Adequate protein intake, sufficient calcium and vitamin D, zinc, healthy fats, and overall calorie availability. Malnutrition can reduce adult height by 5-10 cm.
At what age do children stop growing?
Girls typically stop growing around age 14-16 (2 years after first period). Boys continue growing until 16-18. Growth plates fuse after puberty, making further height gain impossible. Most children reach 95% of adult height by the end of puberty.
What factors besides genetics affect a child's height?
Nutrition, physical activity, sleep quality, and overall health during childhood significantly affect adult height. Adequate protein, calcium, vitamin D, and zinc are essential. Chronic illnesses, hormonal disorders, and certain medications can also impact growth.
Is the mid-parental method accurate for all ethnicities?
The mid-parental height method was developed using Western European populations, so it may be less accurate for other ethnic groups. For children of Asian, African, or Latin American descent, the predicted height may need adjustment. The confidence interval remains at +/-8.5 cm regardless of ethnicity.
When should I consult a doctor about my child's height?
Consult a pediatrician if your child's height is below the 3rd percentile for their age and gender, if growth velocity slows significantly, or if you notice early or delayed puberty. In India, US, and UK, growth charts from WHO are used to assess normal growth patterns.
What is the average height for men and women in different countries?
Average heights vary by country. In the US: men 5'9\" (175 cm), women 5'4\" (163 cm). In the UK: men 5'10\" (178 cm), women 5'5\" (165 cm). In India: men 5'5\" (165 cm), women 5'0\" (152 cm). These averages change over generations due to nutrition and health.