Khamis-Roche Calculator

The Khamis-Roche method is a regression-based adult height prediction formula published in Pediatrics (1994) by Harry Khamis and Alex Roche. It uses five inputs — current age, height, weight, sex, and the average of both parents' heights — to predict the child's adult stature. An erratum correcting certain coefficients was published in 1995. The method was validated on the Fels Longitudinal Study cohort (900+ participants) and remains the most accurate non-invasive height prediction approach available.

The published standard error of estimate is ±2.2 inches for ~80% of boys and ±1.7 inches for ~80% of girls. This means roughly 4 in 5 people will land within those ranges of the predicted height. Individual outcomes depend on nutrition, sleep, illness history, puberty timing, and other environmental factors not captured in the formula.

No — that's one of the method's main advantages. Earlier approaches (like the Greulich-Pyle atlas) require a bone-age X-ray to estimate skeletal maturity. The Khamis-Roche formula achieves similar accuracy using only measurable, non-invasive inputs. Clinical settings may still use X-rays for additional precision, but the Khamis-Roche method works without them.

The original paper covers ages 4–17.5 for boys and 4–16.5 for girls. Accuracy is generally highest in the 8–14 range. Very young children (4–6) still have many growth years ahead, and late-puberty teens (16–17 boys) have very little growth remaining — both factors increase prediction uncertainty, though the ±2 inch range already reflects this.

No — the mid-parental height (Tanner method) is a simpler formula that only uses parents' heights: boys = (father + mother + 5") / 2; girls = (father + mother − 5") / 2. The Khamis-Roche method is more accurate because it also incorporates the child's current height, weight, and age, capturing how far along they are in their growth trajectory rather than just estimating genetic potential.