Khamis–Roche method
B₀ + b₁ × height + b₂ × weight + b₃ × mid-parent height
Uses corrected age- and sex-specific coefficients for ages 4–17.5, with a published average 90% error bound.
Expected Height Calculator
Estimate your child's adult height with the Khamis–Roche or mid-parental height method.
No sign-up. Your data never leaves this browser.
Enter the heights to begin
Your expected adult height, reference range, and optional growth context will appear here.
Enter the parent heights
The mid-parental estimate and general reference range will appear here.
How the Expected Height Calculator Works
Both methods are displayed separately so you can use the available measurements without changing modes.
Mid-parental height method
Boy: (father + mother + 13 cm) ÷ 2
Girl: (father + mother − 13 cm) ÷ 2
Uses parental height and the child's sex. This calculator shows a general ±10 cm reference range.
Frequently Asked Questions
What is an expected height calculator?
An expected height calculator estimates a child's possible adult height. This website provides two separate calculators: the Khamis–Roche method uses the child's age, current height, weight, sex, and both parents' heights, while the mid-parental height method uses only both parents' heights and the child's sex.
Both methods provide informed approximations rather than guarantees. Adult height is also influenced by genetics, nutrition, overall health, sleep, physical activity, and the timing of puberty.
Use the calculated range as a general reference. If a child is growing unusually slowly, crossing major growth-chart percentiles, or if you have concerns about development, discuss the measurements with a qualified pediatric healthcare professional.
Which expected height prediction method should I use?
The mid-parental height method is the simpler choice when you only know both parents' heights. It gives a broad genetic estimate based on parental height and the child's sex.
Khamis–Roche also uses the child's exact age, current height, and current weight. It is designed for healthy children aged 4 to 17.5 years and does not require a bone-age X-ray. Its original equations were developed and validated using white American children, so accuracy may differ for other populations or children with conditions that affect growth.
Method references: the original Khamis–Roche study and the published coefficient erratum.
Is the Expected Height Calculator free?
Yes. The Expected Height Calculator is completely free. No download or account is required, and all calculations run locally in your browser. You can access and use it from a phone, computer, or tablet.
Can I use feet and inches?
Yes. Select “Feet & inches” and the expected height calculator will convert the measurements automatically.
Is the expected height result medically accurate?
No calculator can predict adult height precisely or account for every factor. The result is a rough genetic estimate and should not replace medical assessment.
Accurate measurements plotted over time on an age- and sex-appropriate growth chart are more informative. If growth is a concern, discuss the measurements with a qualified healthcare professional.
How can a child grow taller in a healthy way?
Most height is determined by genetics, so no food, exercise, stretching routine, or supplement can guarantee extra height. Children can support normal growth with a varied diet that provides enough energy and protein, fruits and vegetables, whole grains, and calcium-rich foods; age-appropriate sleep; and regular physical activity.
Track height over time on an age- and sex-appropriate growth chart. If growth slows, height percentiles fall, or puberty appears delayed, consult a pediatric healthcare professional. Do not use growth hormone or height supplements unless recommended by a qualified clinician.
Sources: MedlinePlus Genetics and CDC healthy growth guidance.