Height Calculator
Predict your child's adult height using the mid-parental height formula and Khamis-Roche method. Enter child's current age and measurements, plus both parents' heights.
Child's details 2 methods
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lbs
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in
Parents' heights:
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in
ft
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predicted adult height
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Expected range (±2")
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Mid-parental height
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In centimeters
Method comparison
Mid-Parental Height ✓
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Based on average of both parents' heights. Simple and widely used. Accuracy: ±2 inches (68% confidence).
Khamis-Roche Estimate
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Uses child's age, weight, height, and parent heights. More complex but similar accuracy to mid-parental.
Predicted range at adulthood
Predicted adult height—
Mid-parental height—
Growth remaining (est.)—
Current height vs target—
FAQs
How accurate is height prediction? ›
Height prediction formulas are estimates with inherent uncertainty. The mid-parental height formula has accuracy of approximately ±2 inches (5cm) at 68% confidence, meaning about 68% of children will fall within 2 inches of the predicted height. The Khamis-Roche method is similar. Factors that affect final height beyond genetics include: nutrition (especially protein and calcium), chronic illness, hormonal conditions, stress, and sleep. Children who experience significant illness or malnutrition during growth years may not reach their genetic potential.
When do children stop growing? ›
Most girls complete growth by ages 14–16 (1–2 years after their first period). Boys typically stop growing by ages 17–18. Growth plates (epiphyseal plates) fuse at the end of puberty, ending height gain. Some males may continue slow growth into their early 20s. Signs that growth is slowing: minimal height change over 6 months, later stages of puberty. An X-ray of the hand and wrist (bone age study) can determine how much growth potential remains by assessing growth plate status.