Predict a child's likely adult height from both parents' heights using the mid-parental height method.
Enter both parents' heights and the child's sex, then click Calculate
This free height calculator predicts a child's likely adult height using the mid-parental height method — a widely referenced formula that averages both biological parents' heights and adjusts for the typical height difference between men and women. Enter both parents' heights and the child's sex to get an estimated adult height plus a realistic range around it.
The calculator averages the father's and mother's heights, then adds about 13 cm (5 inches) for a boy or subtracts about 13 cm for a girl, reflecting the average adult height difference between men and women. Because genetics and childhood health both influence final height, the result is shown alongside a typical range (roughly ±8.5 cm) rather than a single guaranteed number.
Parents curious about how tall their child might grow, pediatric nurses and educators explaining growth concepts, and anyone interested in the genetics of height. It's an informational estimate, not a clinical growth assessment — a pediatrician tracking a child's own growth chart over time gives a far more individualized and medically meaningful prediction.
The mid-parental height method this calculator uses
Height is polygenic — influenced by many genes from both parents — so averaging both heights captures more of the genetic signal than using either parent alone.
Adult men average about 13 cm taller than adult women worldwide, so this adjustment shifts the mid-parental average up for boys and down for girls before finalizing the estimate.
Genetic variation and childhood health mean actual adult height regularly falls within roughly ±8.5 cm of the predicted value — showing a range keeps the estimate honest about its precision.
From entering parent heights to reading the predicted range
Type the biological father's height in centimeters, or switch to feet/inches.
Type the biological mother's height in the same unit.
Choose Boy or Girl, since the formula applies a different adjustment for each.
See the predicted adult height and its typical range, shown in both cm and feet/inches.
Predicting height for a boy and a girl from the same parents
Explanation: Both children share the same parents, so the 13 cm sex adjustment is the only thing that changes between scenarios — added for the boy, subtracted for the girl — which is exactly why the two predictions land 13 cm apart.
Where a mid-parental height estimate is commonly used
Get a fun, informational estimate of how tall a young child might grow up to be.
Compare a mid-parental estimate against a pediatrician's own growth-chart projection.
Demonstrate basic heritability concepts in a biology or health class.
Get a general sense of a young athlete's potential adult height for long-term planning discussions.
Compare predicted heights for siblings of different sexes from the same parents.
What this height calculator does well, and where it can't replace medical guidance
Get the most out of a mid-parental height estimate
Summary: This height calculator estimates a child's likely adult height from both parents' heights using the mid-parental method, with a typical ±8.5 cm range shown alongside the prediction — free, instant, and informational rather than clinical. Pair it with NeftCal's BMI Calculator once an adult height is known.
Common questions about predicting a child's adult height
Official pediatric guidance to complement this calculator — not a substitute for medical advice
Other measurement and health tools