Calculators & Tools

Mid Parental Height Calculator

Genetic Target Height & Range

1 What is the Mid Parental Height Calculator?

The Mid-Parental Height Calculator estimates a child's genetic height potential from both parents' heights, as a way to contextualize the child's own growth-chart centile and screen for familial short or tall stature. It applies a different offset for boys versus girls and reports a target height range around the calculated mid-parental height.

2 When to use it

  • Contextualizing a child's height percentile on a growth chart against their genetic (familial) height potential
  • Screening for familial short stature or familial tall stature as a possible explanation for a child's growth pattern
  • Providing parents or clinicians an approximate expected adult height range for counselling discussions
  • Supporting growth-monitoring discussions where a child's growth trajectory needs to be judged relative to parental heights rather than population norms alone

3 Formula & method

Boys: Mid-Parental Height = (Mother's height + Father's height)/2 + 6.5 cm. Girls: Mid-Parental Height = (Mother's height + Father's height)/2 - 6.5 cm. The app then reports a target height range of the calculated MPH +/- 6 cm.

4 Frequently asked questions

Why is 6.5 cm added for boys but subtracted for girls?

This reflects the average height difference between adult men and women; the calculator adds 6.5 cm to the parental average for boys and subtracts 6.5 cm for girls, per the formula shown in the app.

What does the 'target height range' mean?

The app reports mid-parental height +/- 6 cm as an expected target range, reflecting normal variation around the genetic estimate.

Is mid-parental height a guarantee of a child's adult height?

No — the app's own disclaimer states this is a genetic potential estimate only, and actual adult height is also influenced by nutrition, health, and environmental factors.

What height ranges does the calculator accept as valid input?

The app validates mother's height between 120-200 cm and father's height between 130-220 cm.

Is this the same as plotting a growth chart?

No — this tool only computes the mid-parental height estimate; it's meant to be used alongside, not instead of, a standard growth chart when interpreting a child's centile.

For qualified clinicians. This page and the PediAid app are a clinical aid only. Calculations and reference data must be verified against the patient's clinical context, the source guideline and your local protocols before any treatment decision is made.