Predicted Adult Height Calculator

Enter your child's current height, age, and both parents' heights to predict adult height using the Tanner mid-parental formula and WHO growth-curve percentile projection.

Created by Luis GonzalezLast updated: May 9, 2026

How to Use This Calculator

1
Enter Child's Current Height
Input the child's measured height in centimeters. Ensure accuracy for the best prediction.
2
Enter Child's Age
Provide the child's current age in years. This calculator is designed for children between 2 and 18 years old.
3
Enter Father's Height
Input the biological father's adult height in centimeters.
4
Enter Mother's Height
Input the biological mother's adult height in centimeters.
5
Select Biological Sex
Choose 'Male' or 'Female' as this significantly impacts the calculation due to sex-linked growth patterns.
6
Review Your Results
The calculator will display the predicted adult height, along with mid-parental and percentile projections.

Example Calculation

A family wants to estimate the adult height of their 8-year-old son, currently 128 cm tall, whose father is 175 cm and mother is 163 cm.

Child's Current Height

128 cm

Child's Age

8 years

Father's Height

175 cm

Mother's Height

163 cm

Biological Sex

Male

Results

176.3 cm

Tips

Measure Height Accurately

For the most reliable prediction, measure your child's height precisely. Have them stand barefoot against a wall, with their heels, buttocks, and shoulders touching the wall, and use a flat object to mark the top of their head.

Consider Growth Charts

Compare your child's current height and growth trajectory to standard WHO or CDC growth charts. A significant deviation from their established percentile might indicate a need for medical consultation.

Remember Environmental Factors

While genetics are primary, nutrition, sleep, and general health play a role. Ensuring a balanced diet, adequate sleep (e.g., 9-12 hours for school-aged children), and regular physical activity can support optimal growth.

Estimating Future Stature: A Child's Predicted Adult Height

The Predicted Adult Height Calculator offers an estimate of a child's final stature by integrating genetic potential with current growth patterns. Utilizing methods like the Tanner mid-parental height formula and percentile projections based on World Health Organization (WHO) data, this tool provides a comprehensive outlook for parents and healthcare providers. While genetic factors are predominant, environmental influences such as nutrition and health can still contribute a few centimeters to a child's ultimate height.

Genetic and Environmental Factors in Childhood Growth

A child's adult height is primarily determined by genetics, with parental heights offering a strong indicator of potential. However, growth is a complex process influenced by a multitude of factors beyond just inherited genes. Adequate nutrition, particularly sufficient protein, vitamins (like Vitamin D), and minerals (like calcium), is crucial for bone development. Chronic illness, certain medications, and even severe stress can impede growth, while sufficient sleep—often 9 to 12 hours for school-aged children—supports the release of growth hormones. Understanding this interplay helps in fostering an environment conducive to a child reaching their full genetic potential.

Calculating a Child's Adult Height Projection

This calculator combines two well-established methods to provide a robust height prediction: the Mid-Parental Height (MPH) method and a Percentile Projection. The MPH method estimates genetic potential, while the percentile projection considers the child's current growth curve relative to population averages.

Mid-Parental Height (MPH) Calculation:

For Boys: (Father's Height + Mother's Height + 13 cm) / 2
For Girls: (Father's Height + Mother's Height - 13 cm) / 2

Percentile Projection Calculation:

percentile projected height = (child's current height / median height at child's age) × adult median height

The final predicted height is an average of these two calculations, offering a balanced estimate.

💡 For parents considering family planning, understanding biological factors is key. Our Sperm Count Fertility Range Calculator can provide insights into a different aspect of reproductive health.

Estimating an 8-Year-Old's Adult Height

Consider a scenario where parents want to estimate the adult height of their 8-year-old son. He currently measures 128 cm. His father is 175 cm tall, and his mother is 163 cm tall.

Calculate Mid-Parental Height: For a boy: (175 cm + 163 cm + 13 cm) / 2 = 351 cm / 2 = 175.5 cm.
Determine Median Height at Age: A typical 8-year-old boy's median height is approximately 127.3 cm, and the adult male median height is around 176.0 cm.
Calculate Percentile Projection: (128 cm / 127.3 cm) × 176.0 cm = 1.0055 × 176.0 cm ≈ 177.0 cm.
Average the Two Estimates: (175.5 cm + 177.0 cm) / 2 = 176.25 cm.

The calculator predicts an adult height of approximately 176.3 cm (or about 5 feet 9.4 inches) for their son.

💡 While predicting future height, remember that many physical changes occur during growth. For insights into other physiological aspects, our Stretch Mark Risk Calculator explores factors related to skin elasticity during periods of rapid change.

Typical Adult Height Ranges by Population

Adult height is influenced by a complex interplay of genetics, nutrition, and environmental factors, leading to variations across different populations and ethnicities. For instance, the average adult male height in the United States is approximately 175.3 cm (5' 9"), while for females it is about 161.8 cm (5' 3.7"). In some European countries, like the Netherlands, average male heights can exceed 183 cm (6' 0"), reflecting centuries of good nutrition and healthcare. Conversely, populations in certain regions of Southeast Asia or Central America may have average adult heights closer to 160 cm (5' 3") for males and 148 cm (4' 10") for females. These benchmarks highlight how population-level averages, while useful, are broad generalizations and individual predictions must always consider specific genetic backgrounds.

Frequently Asked Questions

How accurate is the predicted adult height calculator?

Predicted adult height calculators, especially those using mid-parental and percentile methods, offer a reasonable estimate with an accuracy typically within a 2-inch (5 cm) range. The accuracy can vary based on individual growth patterns, health factors, and the timing of puberty, making it a projection rather than a definitive outcome.

What is the Tanner mid-parental height method?

The Tanner mid-parental height method is a widely used formula to predict a child's adult height based on the average height of their biological parents, with an adjustment for the child's sex. For boys, 13 cm is added to the parental average, while for girls, 13 cm is subtracted, reflecting typical sex-based height differences.

Can a child's height prediction change over time?

Yes, a child's height prediction can change as they grow, particularly if their growth trajectory deviates from population averages or if they experience early or late puberty. Regular measurements and re-evaluations, especially during significant growth spurts, can refine the prediction, making it more accurate closer to adulthood.