Are you curious about how tall your child will grow to be? You are not alone — adult height is one of the most common questions parents ask during well-child visits. Understanding a realistic height range helps you set expectations for clothing, sports, and overall development without treating a single number as destiny.
Our Height Calculator estimates potential adult stature using two established methods: a multi-variable linear regression analysis (the published Khamis-Roche model) and a simpler parents’ heights only approach. Results appear in centimeters and feet/inches, with a visual comparison chart that plots father, mother, and predicted son or daughter silhouettes side by side — the same family-height view clinicians use when explaining genetics to parents.
New to growth prediction? Read How to Predict Your Child’s Adult Height: Methods, Accuracy & What Parents Should Know for a deeper walkthrough of genetics, nutrition, and when to consult a pediatrician.
About the tool
This is not a novelty widget — it applies peer-reviewed statistical models used in pediatric research. The regression method requires the child’s age, current height, current weight, and both parents’ heights. The parents-only method needs just maternal and paternal stature and returns separate estimates for sons and daughters.
Both modes support US units (feet, inches, pounds) and metric units (centimeters, kilograms). A built-in height converter tab lets you translate any measurement between systems without leaving the page.
Linear regression analysis method
The regression approach models adult height as a linear function of the child’s current measurements and mid-parental height. Coefficients come from the Khamis-Roche method (Khamis & Roche, Pediatrics 1994), derived from the Fels Longitudinal Study. Separate coefficient sets exist for boys and girls at half-year age steps from 4.0 to 17.5 years; the calculator interpolates between rows for decimal ages.
In plain terms: younger children lean more on parental height in the formula, while older children’s own height and weight carry more weight because less growth remains. The published standard error is about ±5.6 cm for boys and ±4.3 cm for girls — useful for setting expectations, not for diagnosing disorders.
Khamis-Roche linear regression (imperial units)
Where H is the child’s height in inches, W is weight in pounds, and M is mid-parent height in inches: (father + mother) ÷ 2. Metric inputs are converted internally before the regression runs.
Parents’ height only method
When you do not know the child’s current measurements — or want a quick genetic ballpark — the mid-parental (Tanner) formula averages both parents’ heights and applies a sex correction of ±6.5 cm (about 2.5 inches). This method is less precise than regression (roughly ±8.5 cm) but needs only two inputs and returns both a son and daughter prediction, which is why the comparison chart shows four silhouettes.
Boys — mid-parental height
Girls — mid-parental height
How to use the height predictor
Regression method (ages 4 – 17.5)
- Select US units or Metric units.
- Choose Linear regression as the prediction method.
- Enter the child’s age, gender, current height, and weight.
- Enter the mother’s and father’s heights (measure barefoot when possible).
- Click Calculate to see the expected adult height and family comparison chart.
Parents’ heights only
- Select your preferred unit system.
- Choose Parents’ heights only.
- Enter maternal and paternal height.
- Click Calculate — you will see separate male and female child predictions plus the four-person chart.
Height converter
Switch to the Height Converter tab to translate centimeters to feet and inches, or imperial measurements to centimeters. Handy when a school form lists cm but your tape measure reads feet.
Examples and use cases
Worked example
Regression method for a 10-year-old boy, 140 cm tall, 35 kg, with mother 165 cm and father 180 cm:
- Predicted adult height ≈ 178 cm (about 5′10″)
- Mid-parental estimate ≈ 177.5 cm + 6.5 cm ≈ 184 cm (parents-only method, less precise)
Real-world use cases
- Pediatric check-up prep: Parents bring a predicted adult height range to discuss growth velocity with their child’s doctor.
- Sports eligibility: A coach estimates whether a young athlete is likely to reach a height threshold for a position over the next few seasons.
- Clothing planning: A family uses the converter tab to compare EU cm sizing with US feet/inches when ordering uniforms online.
Important considerations
Height predictions are statistical estimates, not guarantees. Genetics account for most of the variation in adult stature, but nutrition, sleep, chronic illness, hormones, and puberty timing all matter. A child who matures early or late compared with peers may finish growing sooner or later than the regression assumes because bone age is not part of these formulas.
Re-run the calculator every 6–12 months as your child grows — the prediction typically stabilizes after age 10 and narrows further in the mid-teens. If your child’s height percentile diverges sharply from mid-parental expectation, or growth velocity drops below roughly 4–5 cm per year before puberty, discuss the pattern with a pediatrician. They can order bone-age imaging or lab work when a clinical question exists.
This tool is for educational use on healthy children. It does not replace medical advice. For concerns about growth disorders, eating disorders, or delayed puberty, always consult a qualified healthcare professional.