Mid-parental height
We use (mother + father ± 13 cm) ÷ 2, adding for the male formula and subtracting for the female formula. The family target range is the estimate ±8.5 cm. Imperial entries are converted using exactly 2.54 cm per inch; we retain the 13 cm adjustment for consistent results across unit systems.
Royal Children’s Hospital Melbourne — Short stature, guideline reviewed July 2025. Provides both formulas and the reference range. This is family-height context, not a child-specific confidence interval.
Khamis–Roche: coefficients and age handling
Khamis & Roche (1994), Pediatrics 94:504–507 describes a regression method for children using age, current size and parental stature. Its original population was white American children without growth-altering disease. PubMed lists a March 1995 erratum (95:457).
We checked all 56 age/sex rows against the public UW MSK Radiology implementation, which explicitly records correction of the weight coefficients using the March 1995 erratum. The calculator converts centimeters and kilograms to inches and pounds before applying the equation.
UW MSK Radiology — Adult Stature Predictor
March 1995 erratum — Pediatrics 95:457 Checked October 29, 2026. The publisher’s scanned corrected tables require full-text access; our numerical source is the public UW implementation linked below. We interpolate coefficients linearly between half-year rows and do not extrapolate beyond ages 4–17½. This interpolation is our implementation choice. We do not provide an individual prediction interval or silently clamp a prediction to the current height.
Growth tracking
CDC describes growth charts as tools for tracking growth and says they should not be used as the sole diagnostic instrument. We do not extend a child’s current percentile into a promised adult-height trajectory. CDC — Growth Charts
Army waist-to-height ratio
The Army tool divides recorded average waist by height after conversion to inches and height rounding. It truncates the ratio to three decimals and compares it with 0.550. The result is an estimate from your inputs, not a recorded official assessment.
- Army Directive 2026-13, dated July 1, 2026.
- EXORD 182-26 Annex A, implementing measurement instructions.
- DA Form 5500 (July 2026), waist averages and truncation.
- Army policy hub and FAQ.
There is a difference between the annex’s average-rounding wording and the worksheet’s three-decimal average. The tool takes an already recorded average rather than automating that procedural choice. Read the Army tool’s full measurement notes.
Precision and input boundaries
Height estimates display one decimal centimeter for readability, not as a claim of predictive accuracy. Calculations use unrounded converted inputs. Drawing heights are restricted to 30–250 cm, parent heights to 100–250 cm, Army height to 48–96 in and average waist to 15–100 in. These are practical software limits, not medical or policy eligibility ranges.
Source review
Sources were checked October 29, 2026. This is a dated review, not continuous policy monitoring. Where documents differ, the limitation is stated. No source organization is claimed as a reviewer or endorser of MyHeight.