How are they growing?
Enter your child's measurements and we'll show their percentile, project their adult height, and compare to their genetic potential.
Stylized curves based on WHO/CDC growth standards. Benjamin is the green dot, sitting on the 57th percentile.
If Benjamin stays on the 57th percentile curve, projected adult height:
range: 5'8" to 6'0"
Based on parents' heights:
range: 5'7" to 6'2"
Adult height projection from a child's growth curve is roughly 85% accurate at age 2 or older — meaning a projected 5'11" usually lands within an inch or two. Under 12 months, projections are much less reliable; we'll show a wider range.
We use the same WHO/CDC growth standards your pediatrician uses, plus the mid-parental height formula (boys: parents' average + 2.5"; girls: parents' average − 2.5"), with a 95% confidence interval of ±4 inches.
What we don't do: predict height from genetic tests, account for nutrition or illness, or claim a single number is the answer. Children grow on their own curve, and outliers are common. Sources: WHO Child Growth Standards (2006), CDC Growth Charts (2000), Tanner et al. (1970).
A typeset keepsake — your baby's name, the projected adult height, and the 95% range. Cream + sage matte paper.
Mid-Parental Height (MPH) is the standard tool pediatricians use to project adult stature. We add the WHO/CDC growth-curve percentiles for the current age so you see both: where they sit on the population curve right now, and where they're statistically heading.
The ±4-inch range captures population variance honestly — most online calculators undersell the spread.
- Doesn't account for grandparent heights, nutrition, or sex-chromosome variants.
- Constitutional growth delay (late bloomers) and growth hormone disorders are out of scope.
- Stylized curves — visual only, not clinical-grade percentile lookup.
Free, attribution-only. One iframe — your readers stay on your page, the calculator works exactly the same, and the math runs on willthey.baby so we keep it accurate.