Projected Adult Height Calculator
Estimate a child’s likely adult height using two methods: mid-parental target height and current-growth projection. Enter values in centimeters.
Educational estimate only. This tool does not replace a pediatric evaluation.
How this projected height calculator works
This calculator gives a practical estimate of adult height by combining family genetics with current growth status. It uses two common ideas:
- Mid-parental (target) height: a genetics-based estimate from mother and father heights.
- Growth-completion projection: estimates adult height from current age and current height.
The final result is a blended estimate, plus a likely range. It is useful for planning and context, but no online tool can perfectly predict a final adult height.
Formulas used in the calculator
1) Mid-parental target height
The classic formulas are:
- Boys: (Father height + Mother height + 13) / 2
- Girls: (Father height + Mother height - 13) / 2
That gives a center target in centimeters. In clinical practice, a normal “target range” around this value is often considered.
2) Current growth projection
Children reach adult height gradually. The calculator uses age-based completion factors (different for boys and girls). Example: if a child has reached 80% of expected adult height, adult height is approximated as current height / 0.80.
This method can be sensitive to timing of puberty, so it works best as one component, not a standalone rule.
3) Blended estimate
The final estimate is a weighted blend:
- 60% from mid-parental target height (genetics)
- 40% from current growth projection
This creates a more balanced estimate for most families.
How to interpret your results
- Projected adult height: The calculator’s central estimate.
- Likely range: A practical band around the estimate. Final adult height may land above or below this.
- Mid-parental target: Your genetics-based reference point.
If growth appears to be slowing abruptly, crossing major percentiles, or differs greatly from family patterns, discuss it with a pediatrician or pediatric endocrinologist.
What influences final adult height?
Genetics
Parental height is the strongest factor. Family pattern matters, including variation in siblings and extended family.
Nutrition and overall health
Balanced nutrition, protein intake, micronutrients, and chronic disease management all affect growth velocity.
Sleep and activity
Regular sleep and physical activity support healthy development and hormonal rhythms associated with growth.
Puberty timing
Early or late puberty can significantly shift temporary growth expectations. That is one reason projected height can change over time.
Tips for better tracking
- Measure height at the same time of day with shoes off.
- Use a wall-mounted stadiometer or consistent method.
- Track changes every 3–6 months instead of weekly.
- Compare growth trends, not single data points.
Frequently asked questions
Is this calculator accurate?
It is a useful estimate, not a diagnosis. Clinical prediction can include growth charts, bone age imaging, puberty stage, and medical history.
Can a child outgrow the prediction?
Yes. The result is probabilistic. Puberty timing, health changes, and measurement quality can all shift projections.
Why does the estimate differ from other calculators?
Different tools use different assumptions, growth tables, and weightings between genetics and current measurements.
Bottom line
A projected height calculator is best used as a planning guide. Recalculate over time as new measurements come in, and use clinical guidance if growth patterns are concerning. Trends across months and years are far more meaningful than a single number today.