Mid-Parental Height Formula
On this page
Mid-parental height combines the biological parents' heights with a sex-specific adjustment to estimate a broad target range. It is a screening estimate rather than an individual growth forecast.
Formula and variables
The calculation is reliable only when the variables, units and denominator match the stated method. The steps below keep those choices visible.
Mid-parental formulas provide a rough familial estimate. Khamis-Roche uses a child's current age, sex, height and weight plus parental heights and was developed from a specific reference population. It should not be applied outside its supported ages or described as universally validated.
Step by step
Convert inputs to the units required by the formula. Identify the correct baseline or denominator. Substitute the values without premature rounding. Calculate with full working precision. Round once at the end and attach the correct unit or percent sign.
Worked example
A height calculator can either convert a measured height or estimate a child's adult height; those are different jobs. Unit conversion is exact apart from rounding. Adult-height prediction is uncertain and depends on the method, age, sex input and reference population. Show the selected method and a range, never a guaranteed final height.
How to verify the answer
Repeat the calculation with an independent method, reverse the operation when possible, and test a known reference value. Check zero, negative, minimum, maximum, and unit-equivalent inputs before publishing the implementation.
Display a central estimate plus the method's documented prediction interval or an explicitly labeled broad planning range. Genetics, puberty timing, health, nutrition and population differences influence adult height. A calculator cannot assess growth velocity or diagnose a growth disorder.
Common mistakes
- Using inconsistent units before applying the calculation.
- Rounding intermediate values and carrying that error into the final result.
- Treating an estimate, reference chart, or general rule as an official or professional decision.
- Using the Height Calculator without checking whether its stated method matches the user's situation.
Use the result
Open the Height Calculator to run the calculation with displayed inputs and method details. Then use this guide to check the interpretation, boundary, or next decision. Keep the source measurements and unrounded result when the value will be reused.
Frequently asked questions
What does Mid-Parental Height Formula mean in practice?
Mid-parental height combines the biological parents' heights with a sex-specific adjustment to estimate a broad target range. It is a screening estimate rather than an individual growth forecast.
How does this page relate to the Height Calculator?
The calculator performs the numeric operation. This guide covers method, explains the assumptions, and shows the checks needed before the result is used.
Should intermediate values be rounded?
Keep working precision through unit conversion and intermediate steps unless the controlling rule requires a specific intermediate rounding sequence. Round the displayed result once and state the rule.
What is the main limitation?
Display a central estimate plus the method's documented prediction interval or an explicitly labeled broad planning range. Genetics, puberty timing, health, nutrition and population differences influence adult height. A calculator cannot assess growth velocity or diagnose a growth disorder.
Sources
- https://www.cdc.gov/growthcharts/
- https://www.who.int/tools/child-growth-standards
- https://pubmed.ncbi.nlm.nih.gov/1941365/
Prepared for CalculatorGeek on September 9, 2026. Confirm the source is still current at publication. Do not display a reviewed-by or last-reviewed claim until the review is actually completed and recorded.
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