Baby Growth Percentile Calculator (WHO Charts, 0–5 Years)
Find your baby's or toddler's percentile for weight, length/height and head circumference using the WHO Child Growth Standards (0–5 years) — with z-score and the weights or lengths at the 3rd, 50th and 97th percentiles.
For general information only — not medical advice. Results are estimates; talk to a doctor or qualified health professional about your own health.
How to use
- 1Choose boy or girl and enter the age in months.
- 2Enter the weight, length/height or head circumference.
- 3See the percentile and where it sits on the growth chart.
How it's calculated
WHO LMS method: z = ((measurement ÷ M)^L − 1) ÷ (L × S), with L, M and S for the child's sex and age (interpolated between months). Percentile = normal distribution of z.
Frequently asked questions
What percentile is normal?
Anything between roughly the 3rd and 97th percentile is usually considered normal. What matters most is following a steady curve over time — sudden jumps or drops across percentile lines are worth discussing with your health visitor or paediatrician.
Why WHO charts?
The WHO standards describe how healthy breastfed children grow in optimal conditions, and are recommended by the CDC for children under 2 in the US and used in the UK (UK-WHO charts) and many other countries.
Length or height?
Under 2 years children are measured lying down (length); from 2 years standing (height), which reads about 0.7 cm less.