WHO Growth z-Score (0-2 yr)
WHO 2006 growth z-score (LMS method): weight-for-age or length-for-age z-score and percentile for a child 0–24 months.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Sex
- Male
- Measurement
- Weight-for-age (kg)
- Age
- 6
- Measured value
- 5.5
Result: 5.5 kg weight-for-age at age 6 mo: z -3.27 (0.1th percentile) — severely low (z below −3) — severely underweight.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Transform
- the measured weight or length is converted to a z-score by the WHO LMS transform z = ((X/M)^L − 1) / (L·S) (length-for-age uses L = 1).
- Bands
- z below −2 is low (underweight, or stunted for length-for-age); z below −3 severely low; z above +2 high.
What you enter
- Sex
- Measurement
- Age (months, 0–24)
- Measured value (kg or cm)
How this is calculated
- Range
- weight/length-for-age applies to ages 0 to 24 months; at 2 years and above use the CDC BMI-for-age tool.
WHO Multicentre Growth Reference Study Group. WHO Child Growth Standards based on length/height, weight and age. Acta Paediatr Suppl. 2006;450:76-85. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.