# What is the mid-parental height?

Works out a child’s mid-parental target height from both parents’ heights with Tanner’s method, (father + mother ± 13 cm) ÷ 2, and the ± 8.5 cm target range.

- Page: https://www.acalculator.org/health/mid-parental-height-calculator
- JSON spec: https://www.acalculator.org/health/mid-parental-height-calculator.json
- Version: f38e5f128a3b

## Default answer

Example with the default inputs (Child’s sex Boy, Father’s height 5 ft 10 in, Mother’s height 5 ft 4 in): The mid-parental height is 69.6 in (5 ft 9.6 in), with a target range of 66.2 in to 72.9 in.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| sex | Child’s sex | The child’s sex, which moves the target up or down by 6.5 cm. |
| father | Father’s height | The biological father’s adult height. |
| mother | Mother’s height | The biological mother’s adult height. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| target | Mid-parental height | The target height: (father + mother + 13 cm) ÷ 2 for a boy, − 13 cm for a girl. |
| feetInches | In feet and inches, or metres | The mid-parental height in feet and inches (US) or in metres (Metric). |
| targetCm | In centimetres | The mid-parental height in centimetres. |
| low | Target range from | The low end of the target range: the mid-parental height − 8.5 cm. |
| high | Target range up to | The high end of the target range: the mid-parental height + 8.5 cm. |
| average | Parents’ average height | The plain average of the two heights, before the 6.5 cm sex adjustment. |

## Method

Mid-parental height = (father’s height + mother’s height + 13 cm) ÷ 2 for a boy, or − 13 cm for a girl; target range ± 8.5 cm.

## Assumptions

- Men are on average about 13 cm taller than women, so the parents’ average is moved 6.5 cm up for a boy and 6.5 cm down for a girl (Tanner 1970).
- The target range of 8.5 cm either side is Tanner’s, about the 3rd to 97th centile; later work widened it to about 9 cm for girls and 10 cm for boys.
- The parents are the biological parents, and the child grows in good health and nutrition.
- This is a rough guide for families, not a medical prediction. A pediatrician can use growth charts and bone age for more.

## Worked examples

1. sex = male, father = 1.778, mother = 1.6256 gives target = 1.7668, low = 1.6818, high = 1.8518, average = 1.7018. Source: Tanner JM, Goldstein H, Whitehouse RH, Standards for children’s height at ages 2–9 years allowing for heights of parents, Arch Dis Child 1970;45:755–762, https://doi.org/10.1136/adc.45.244.755; Zeevi D et al., Accurate Prediction of Children’s Target Height from Their Mid-Parental Height, Children (Basel) 2024 (NIH PMC: Tanner’s ± 6.5 cm sex adjustment and ± 8.5 cm range), https://pmc.ncbi.nlm.nih.gov/articles/PMC11352326/, retrieved 2026-10-02.
2. sex = female, father = 1.778, mother = 1.6256 gives target = 1.6368, low = 1.5518, high = 1.7218. Source: Tanner JM, Goldstein H, Whitehouse RH, Standards for children’s height at ages 2–9 years allowing for heights of parents, Arch Dis Child 1970;45:755–762, https://doi.org/10.1136/adc.45.244.755.
3. sex = female, father = 1.8, mother = 1.65 gives target = 1.66, targetCm = 1.66, average = 1.725. Source: Tanner JM, Goldstein H, Whitehouse RH, Standards for children’s height at ages 2–9 years allowing for heights of parents, Arch Dis Child 1970;45:755–762, https://doi.org/10.1136/adc.45.244.755.

## FAQ

### What is mid-parental height?

The average of the parents’ heights, moved for the child’s sex. Doctors use it as a target height: the adult height a child of these parents is most likely to reach. It is the centre of a range, not an exact forecast.

### How do I calculate mid-parental height?

In centimetres: for a boy, (father + mother + 13) ÷ 2; for a girl, (father + mother − 13) ÷ 2. In inches, use 5 instead of 13. A boy with a 177.8 cm (5 ft 10 in) father and a 162.6 cm (5 ft 4 in) mother has a target of (177.8 + 162.56 + 13) ÷ 2 = 176.7 cm, about 5 ft 9.6 in.

### Why add or take away 13 cm?

Adult men are on average about 13 cm taller than adult women. Adding 13 cm for a boy (or taking 13 cm away for a girl) and halving moves the parents’ average 6.5 cm toward the child’s sex.

### What is the target range?

Tanner put the range at 8.5 cm either side of the mid-parental height, about the 3rd to 97th centile. Later work widened it to about 9 cm for girls and 10 cm for boys. A child far outside the range may be worth a talk with a pediatrician.

### Is mid-parental height accurate?

It is a rough guide. Two children of the same parents can end up far apart, and nutrition, health and puberty timing all matter. A pediatrician can add the child’s growth chart and bone age.

### How is this different from the height calculator?

It is the same Tanner method. This page leads with the mid-parental height and also shows the parents’ plain average; the height calculator leads with the predicted adult height.

## Sources

- Tanner JM, Goldstein H, Whitehouse RH. Standards for children’s height at ages 2–9 years allowing for heights of parents. Arch Dis Child. 1970;45(244):755–762. https://doi.org/10.1136/adc.45.244.755
- Zeevi D, Ben Yehuda A, Nathan D, Zangen D, Kruglyak L. Accurate Prediction of Children’s Target Height from Their Mid-Parental Height. Children (Basel). 2024 (Tanner’s ± 6.5 cm sex adjustment and ± 8.5 cm range; later ± 9 cm for girls and ± 10 cm for boys), retrieved 2026-10-02. https://pmc.ncbi.nlm.nih.gov/articles/PMC11352326/
- Centers for Disease Control and Prevention. Growth charts, retrieved 2026-10-02. https://www.cdc.gov/growthcharts/