Baby percentile calculator (WHO, 0–24 months)
Enter your baby's birth date, sex, and a recent weight, length, or head circumference. You'll see their percentile on the WHO Child Growth Standards, the charts pediatricians use.
Source: WHO Child Growth Standards . Percentiles are calculated from the WHO LMS reference data (weight-for-age, length/height-for-age, and head-circumference-for-age). Not medical advice. Share results with your pediatrician.
What a percentile really means
Three things every parent should know before they read a growth chart.
A position, not a score
If your baby is at the 62nd percentile, about 62 out of 100 healthy babies their age weigh less. It says where they sit on the curve. Never "better" or "worse".
Follow the curve, not the number
Pediatricians watch the trend over time. A temporary dip around an illness is normal. A steady line is a good sign.
The typical band is wide
About 95% of healthy babies fall between the 3rd and 97th percentiles. Sitting on either side of the median is completely normal.
WHO median weight-for-age, 0–24 months
The median (50th percentile) weight in kilograms by age. Half of healthy boys or girls weigh more, half weigh less. Use the calculator above for any age in days and any percentile.
| Age | Boys (kg) | Girls (kg) |
|---|---|---|
| Birth | 3.35 | 3.23 |
| 1 mo | 4.45 | 4.17 |
| 2 mo | 5.57 | 5.13 |
| 3 mo | 6.39 | 5.86 |
| 4 mo | 7.01 | 6.43 |
| 5 mo | 7.52 | 6.91 |
| 6 mo | 7.95 | 7.31 |
| 9 mo | 8.89 | 8.22 |
| 12 mo | 9.65 | 8.95 |
| 15 mo | 10.31 | 9.60 |
| 18 mo | 10.94 | 10.23 |
| 24 mo | 12.15 | 11.47 |
Source: WHO Child Growth Standards . Median weight-for-age values, rounded to two decimals.
Frequently asked questions
Straight answers to the questions parents ask most about baby growth.
It's natural to want one clear answer, so here it is: almost any percentile is fine on its own. About 95% of healthy babies sit between the 3rd and 97th percentiles, and a baby at the 5th or 95th can be perfectly healthy. What your pediatrician actually watches is the trend — whether your baby follows their own curve across several measurements. One number, on its own, is rarely news.
Turn measurements into a growth story
The growth and milestones tracker in Storklet plots each measurement on the WHO percentile chart automatically, so the story builds itself. It's exactly what your pediatrician will want to see.
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WHO percentile charts
Every measurement plotted on clinical curves
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The trend over months
See your baby follow their own curve
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Milestones alongside
First words and first steps, in the same story
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Measurement
8.2 kg · 62nd percentile
Growth
Follows own curve