Height converter and mid-parental adult height estimate
Choose a direct height conversion or enter both parents' heights for a rough adult-height estimate. HitEquals shows centimeters, feet and inches, the mid-parental formula and the method's broad expected range.
Inputs used by this calculator
Height Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Calculation | Estimate a child's adult height | Estimate a child's adult height · Convert a height | Chooses which Height Calculator method or unknown the engine evaluates. |
| Measurement system | US — total inches | US — total inches · Metric — centimeters | Selects the unit or conversion path used by Height Calculator. |
| Child's sex for the equation | Girl | Girl · Boy | Supplies the child's sex for the equation quantity used by the published equation or result breakdown. |
| Height to convert (total inches or cm) | 67 | 20 to 300 | Selects the unit or conversion path used by Height Calculator. |
| Father's height (inches or cm) | 70 | 48 to 250 | Supplies the father's height (inches or cm) quantity used by the published equation or result breakdown. |
| Mother's height (inches or cm) | 65 | 48 to 250 | Supplies the mother's height (inches or cm) quantity used by the published equation or result breakdown. |
What the height calculator does
Conversion mode translates one height between exact metric and US customary representations. Child estimate mode applies the American Academy of Pediatrics mid-parental method to the biological parents' heights.
Mid-parental height formula
First average the two parental heights in inches. Add 2.5 inches for a boy or subtract 2.5 inches for a girl. The AAP describes the result as a rough estimate with about four inches of possible variation in either direction.
boy estimate=(father+mother)÷2+2.5 ingirl estimate=(father+mother)÷2−2.5 inrough range=estimate±4 inWorked example
A 178 cm father is about 70.08 inches and a 165 cm mother is about 64.96 inches. Their average is 67.52 inches. Subtracting 2.5 inches gives 65.02 inches, or about 165.2 cm, for a girl.
Exact height conversions
The international inch is exactly 2.54 centimeters. A foot contains exactly 12 inches. Feet-and-inches display is rounded for reading while the engine retains the full converted value.
centimeters=inches×2.54total inches=centimeters÷2.54Why actual adult height can differ
Genetics, health, nutrition, hormones, puberty timing and measurement history all matter. The midpoint does not use the child's growth velocity or skeletal maturity. The AAP notes that bone-age evaluation can provide a more accurate clinical prediction.
When a growth chart matters
A child's current stature should be interpreted by age and sex across repeated visits. CDC growth charts are reference tools; a percentile or this family estimate alone does not diagnose a growth disorder.
Height conversion reference
| Measure | Exact equivalent |
|---|---|
| 1 inch | 2.54 cm |
| 1 foot | 12 inches |
| 1 foot | 30.48 cm |
| 1 meter | 100 cm |
Frequently asked questions
How accurate is the child height estimate?
The AAP describes the mid-parental method as rough and gives a range about four inches above or below the estimate.
Does the calculation use the child's current height?
No. This method uses parental heights and equation sex; clinical predictions may also use growth history and bone age.
Why are boy and girl formulas different?
The AAP shortcut adjusts the parental average by 2.5 inches in opposite directions.
How do I enter 5 feet 7 inches?
Convert it to 67 total inches in US mode.
Is one inch exactly 2.54 centimeters?
Yes. The conversion is exact.
Can this diagnose short stature?
No. Growth concerns require age-specific measurements and clinical assessment.
What to keep in mind
This is a rough family-height estimate, not a diagnosis or promise. Pediatric growth assessment uses serial measurements, age- and sex-specific charts and, when needed, clinical evaluation.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.