Child Height Predictor
Estimate your child adult stature using evidence-based pediatric endocrinology algorithms. This tool combines the established Tanner Mid-Parental Target Height method with age-stature growth trajectory curves to calculate projected adult height, imperial feet-and-inch conversions, and statistical target ranges.
Biological sex influences timing and magnitude of adolescent growth spurts
Current chronological age in completed years
Standing barefoot height measured flat against a wall
Paternal standing height in centimetres (e.g. 178 cm = 5 ft 10 in)
Maternal standing height in centimetres (e.g. 164 cm = 5 ft 4.5 in)
Estimated adult stature based on mid-parental genetics and current trajectory
How to Use This Calculator
- Choose the child biological sex to account for male vs. female growth curves.
- Enter the child exact age in years and current standing barefoot stature.
- Input both biological parents standing adult heights in centimetres.
- Review the predicted adult height in both feet/inches and centimetres.
- Observe the ±6 cm clinical confidence interval representing normal polygenic variation.
Formula & Calculation Methodology
The Tanner Mid-Parental Height formula adjusts for the average 13 cm (5.1 inch) sexual dimorphism in adult height between men and women. The Khamis-Roche method further refines prediction using the child current stature and chronological maturity age.
Worked Example
An 8-year-old boy (128 cm) with a father of 178 cm and mother of 164 cm
Frequently Asked Questions
How accurate is the Tanner Mid-Parental Height method?↓
The mid-parental method predicts adult height within ±5 to 6 cm (approximately 2 inches) for roughly 85% to 90% of healthy children. Unforeseen factors such as childhood nutrition, sleep quality, chronic illness, and timing of puberty account for the remaining variance.
Is the age 2 height-doubling rule accurate?↓
Doubling a child height at age 2 (for boys) or at 18 months (for girls) is a popular heuristic that provides a rough benchmark. However, the Khamis-Roche and mid-parental formulas are clinically superior because they incorporate parental genetics.
How does the adolescent growth spurt affect height prediction?↓
Early bloomers experience peak height velocity before their peers, while late bloomers (constitutional delay of growth) may seem temporarily short before catching up during late adolescence. Both groups generally reach their genetically determined adult height.
What role does parental height play in determining child stature?↓
Twin and family studies indicate that genetics account for approximately 60% to 80% of final adult height in well-nourished developed populations, with environmental factors like nutrition and health accounting for the remainder.
When should a parent consult a pediatric endocrinologist regarding growth?↓
Consult a pediatric specialist if a child growth rate drops significantly below 4 cm (1.5 inches) per year between age 4 and puberty, or if their height trajectory falls below the 3rd percentile on standard CDC/WHO charts.
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Source Citation & Disclaimer
Informational tool only; not licensed tax, legal, or financial advice.