QuickCalculators predicts adult height from the parents' heights using the mid-parental method, reports a plus-or-minus 4 inch error range beside the point estimate, and converts among feet, inches, and centimetres. Enter both parents' heights and the child's sex; read the prediction as a range, not a target.
Predict an adult height from the parents' heights
Mid-parental height averages the parents' heights with a sex adjustment, then treats that figure as a central adult prediction. Height Calculator applies the common +2.5 inch adjustment for boys and -2.5 inch adjustment for girls around the parental midpoint (or the metric equivalents). Genetics explain much of stature; the tool does not turn the estimate into a goal.
Example: parents at 5 ft 10 in and 5 ft 4 in. The mid-parental path for a boy centers near 5 ft 10 in before the error band. Exact arithmetic depends on unit conversion to a single system before averaging. The result is a prediction, not a promise.
Convert between feet, inches and centimetres
Height inputs and outputs can switch among feet-and-inches and centimetres without changing the underlying mid-parental math. QuickCalculators normalizes awkward inch overflows such as 5 ft 14 in into 6 ft 2 in when displaying US units. One inch equals 2.54 centimetres for those conversions.
Parents entered in mixed unit styles still need a shared internal metre or inch value before averaging. The converter exists so the prediction and the error band can be read in the unit family preferred on screen.
Avoid this common mistake
Height prediction carries an error range of about plus or minus 4 inches. A point estimate of 5 ft 11 in means a plausible adult band from about 5 ft 7 in to 6 ft 3 in. Treating the single central number as exact adult height overstates what mid-parental math can deliver.
More accurate clinical methods need bone-age imaging or licensed coefficient tables such as Khamis-Roche (1994) context. This page uses mid-parental height and states that limit plainly. No advice on becoming taller belongs on a prediction tool.
Compare the height prediction methods
Mid-parental height is simple and transparent from two adult heights. Khamis-Roche and bone-age methods can reduce error when current child measurements and imaging are available under proper clinical use. QuickCalculators stays with mid-parental math and the plus-or-minus 4 inch framing for the point estimate.
Roughly 60 to 80 percent of height variation is genetic in population studies, with the remainder outside a child's control as a self-improvement project. The calculator therefore reports a range and stops. Attractiveness or worth language does not appear.
Frequently asked questions
How tall will a child be as an adult?
How tall a child will be as an adult cannot be known exactly from parents alone; mid-parental height supplies a central estimate with about a 4 inch error band. Enter both parents' heights and sex on this page to see that range. Clinical methods may refine the estimate with more data.
How do you calculate mid-parental height?
To calculate mid-parental height, average the parents' heights and adjust by about +2.5 inches for boys or -2.5 inches for girls (metric equivalents apply). That adjusted midpoint is the point estimate before applying the error range. Unit conversion happens before the average.
How accurate is a height prediction?
A mid-parental height prediction is accurate only within roughly plus or minus 4 inches for many children. The point estimate sits in the middle of that band. Bone-age and coefficient methods can improve accuracy when used clinically.
What determines a person's height?
A person's height is determined largely by genetics, with nutrition and health also contributing across development. Population studies often attribute about 60 to 80 percent of variation to genetic factors. This tool uses parental heights as a genetic proxy, not a complete model.
What is the Khamis-Roche method?
The Khamis-Roche method is a height-prediction approach that uses current child measurements and parental heights with published coefficients, typically without bone age. It can be more accurate than mid-parental height alone when those inputs exist. This page does not run Khamis-Roche tables.
At what age do people stop growing?
People stop growing at different ages; many reach near-adult height in the late teens after puberty completes, with some variation by sex and individual. The calculator predicts adult stature, not the calendar year growth ends. Clinical growth charts track progress over time.
Summary
Height Calculator estimates adult stature from mid-parental height and always pairs the point estimate with about a plus-or-minus 4 inch band. A reading near 5 ft 11 in implies a wide interval such as 5 ft 7 in to 6 ft 3 in.
Unit conversion supports feet, inches, and centimetres. The page uses mid-parental math only and does not offer tips on growing taller.