Predicted Adult Height Calculator

Work out predicted adult height instantly with clear inputs, formula shown and shareable results.

About Predicted Adult Height Calculator

This is the mid-parental (Tanner) method: average the parents' heights, then add 6.5 cm for a boy or subtract 6.5 cm for a girl, with a plus or minus 8.5 cm range covering most outcomes. Target height from parents is the standard first check on whether a child's growth curve is where genetics would put it, before anything else is investigated.

Formulas

Mid-parental height

mid-parental = (father's height + mother's height) / 2

Target height

boys = mid-parental + 6.5 cm; girls = mid-parental - 6.5 cm, plus or minus 8.5 cm

Worked example

With the default values below, Predicted Adult Height Calculator returns Predicted adult height of 178.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Father's heightminimum 100 cm: 178 cm
Mother's heightminimum 100 cm: 165 cm
Child's sexone of Boy, Girl: Boy

Results

Predicted adult height: 178.0 cm
Lower end of the likely range: 169.5 cm
Upper end of the likely range: 186.5 cm
Mid-parental height: 171.5 cm

Step by step

1Values used
2Mid-parental height
3Target height
4Predicted adult height= 178.0 cm
5Lower end of the likely range= 169.5 cm
6Upper end of the likely range= 186.5 cm
7Mid-parental height= 171.5 cm

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Predicted Adult Height figure worked out?

mid-parental = (father's height + mother's height) / 2. This is the mid-parental (Tanner) method: average the parents' heights, then add 6.5 cm for a boy or subtract 6.5 cm for a girl, with a plus or minus 8.5 cm range covering most outcomes.

Why does this matter?

Target height from parents is the standard first check on whether a child's growth curve is where genetics would put it, before anything else is investigated.

What do I need to enter?

Enter father's height, mother's height, child's sex. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.