Baby Percentile Calculator — Baby Weight & Height Percentile
Calculators
4.3
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Updated Apr 8
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–th percentile
z-score: –
0255075100
–
Based on official WHO Child Growth Standards data. Percentiles are computed with the WHO LMS method from the published WHO tables (weight-for-age and length/height-for-age, 0–60 months). This is an informational tool, not medical advice — always consult your pediatrician about your child's growth.
How does the baby percentile calculator work?
Enter your baby's age in months (0–60), sex, and either weight or length/height. The calculator looks up the official WHO LMS parameters (L, M, S) for that exact age and sex, then computes the z-score with the LMS formula:
z = ((value ÷ M)^L − 1) ÷ (L × S)
- WHO data: uses the published WHO Child Growth Standards tables — the same reference pediatricians use worldwide.
- Percentile: the z-score is converted to a percentile with the standard normal distribution (e.g. z = 0 → 50th percentile).
- Typical range: most healthy babies fall between the 3rd and 97th percentiles. A single measurement outside this range is not a diagnosis — growth trends over time matter more.
- Private: all WHO data is embedded in this page — everything runs in your browser with no uploads.
Growth charts are screening tools. If you have any concern about your child's growth, talk to your pediatrician.
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Tool Information
Category
Calculators
Updated
Apr 8
Status
Active
Rating
4.3
Type
Free Tool
10,091 people used this tool
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