Mid Parental Height Calculator

What is Mid Parental Height Calculator?

A Mid Parental Height (MPH) Calculator estimates a child’s expected adult height using the average of the biological parents’ heights with a sex‑specific adjustment. This pediatric rule of thumb provides a target height and a typical range reflecting natural family variation. It is most useful for context—answering, “Is my child’s projected adult stature broadly consistent with family heights?”—not as a guarantee. The method assumes adequate health, nutrition, and timing of puberty. Results are displayed with responsive formulas and unit conversions for centimeters, feet, and inches, so you can verify the arithmetic at a glance and copy steps into notes or reports.

About the Mid Parental Height Calculator

The calculator accepts heights in feet+inches or centimeters, performs unit conversions, and returns the sex‑adjusted MPH with a conventional ±8.5 cm target range. It optionally reports a standardized offset for a measured or predicted adult height using an approximate familial standard deviation \(\sigma\approx4.5\,\text{cm}\). This helps interpret whether a child is well within the expected family band or unusually above/below it. The tool emphasizes transparency: each substitution, average, and unit conversion is shown in line, and the range is computed automatically for convenient printing or sharing.

How to Use this Mid Parental Height Calculator

Select the child’s sex to apply the correct MPH adjustment.
Enter the father’s and mother’s heights (either in cm or in ft+in; the calculator converts automatically).
Click calculate to see \(\text{MPH}\) and the target range \(\text{MPH}\pm8.5\,\text{cm}\) (and inches).
Optionally enter a measured or predicted adult height to compute a \(z\) offset from family expectation.
Use results as context only; clinical decisions require professional evaluation, growth charts, and, if indicated, bone age.

Examples

Example 1: Boy prediction (inputs in cm)

\(H_{\mathrm{father}}=180\,\text{cm},\; H_{\mathrm{mother}}=165\,\text{cm}\).

Example 2: Girl prediction (inputs in ft+in)

\(H_{\mathrm{father}}=5'11\"\;(71\,\text{in}),\; H_{\mathrm{mother}}=5'4\"\;(64\,\text{in})\).

Example 3: z‑offset from family target

Predicted adult height \(=172\,\text{cm}\) for a girl with \(\text{MPH}=165\,\text{cm}\).

FAQs

How accurate is the mid parental height method?

It’s a family‑based estimate, not a guarantee. About two‑thirds of healthy children finish within ±6–7 cm of MPH.

Why add 13 cm for boys and subtract 13 cm for girls?

It adjusts for average adult sex differences in stature so the family midpoint is aligned to the child’s sex.

Can I enter heights in feet and inches?

Yes—enter ft and in; the calculator converts to centimeters internally using \(\text{cm}=2.54\times\text{in}\).

Does early or late puberty affect results?

Yes. Timing of puberty changes growth duration. MPH offers context; clinical assessment may use bone age and growth charts.

What if one parent is much taller or shorter?

The range around MPH accommodates variation, but extreme parental differences widen real‑world outcomes.

Do nutrition and health matter?

Absolutely. Chronic illness, undernutrition, or systemic conditions can reduce adult height irrespective of family averages.

Can adoption or unknown parent heights be handled?

Without biological heights, MPH cannot be computed. Use growth percentiles and medical guidance instead.

Should twins use the same MPH?

Yes—the family target applies to both, though individuals may differ within the range.

Is ±8.5 cm the only valid range?

It’s a common convention (roughly ±2 SD). Some clinicians use slightly different bands; context matters.