Baby weight chart by month
This chart shows the WHO weight-for-age percentiles for baby girls and boys from birth to 24 months, in kg with lb for the median. Use the calculator below to find your baby’s weight percentile for their exact age. Separate charts in kg and lbs: baby boy weight chart · baby girl weight chart.
Enter a date of birth and at least one measurement to see the percentile.
Key numbers
- At birth, the WHO median weight is 3.2 kg (7.1 lb) for girls and 3.3 kg (7.4 lb) for boys.
- At 6 months, the median is 7.3 kg (16.1 lb) for girls and 7.9 kg (17.5 lb) for boys.
- At 12 months, the median is 8.9 kg (19.7 lb) for girls and 9.6 kg (21.3 lb) for boys.
- At 24 months, the median is 11.5 kg (25.3 lb) for girls and 12.2 kg (26.8 lb) for boys.
- Median weight doubles birth weight at about 5 months for girls and 4 months for boys, and is roughly 2.8 times birth weight at 12 months.
Girls: average weight and percentiles by month (WHO)
Values in kg at each percentile. The median is the average weight for that age; it is also shown in lb.
| Age | 3th | 15th | Median | 85th | 97th | Median (lb) |
|---|---|---|---|---|---|---|
| Birth | 2.4 | 2.8 | 3.2 | 3.7 | 4.2 | 7.1 |
| 1 month | 3.2 | 3.6 | 4.2 | 4.8 | 5.4 | 9.2 |
| 2 months | 4.0 | 4.5 | 5.1 | 5.9 | 6.5 | 11.3 |
| 3 months | 4.6 | 5.1 | 5.8 | 6.7 | 7.4 | 12.9 |
| 4 months | 5.1 | 5.6 | 6.4 | 7.3 | 8.1 | 14.2 |
| 5 months | 5.5 | 6.1 | 6.9 | 7.8 | 8.7 | 15.2 |
| 6 months | 5.8 | 6.4 | 7.3 | 8.3 | 9.2 | 16.1 |
| 7 months | 6.1 | 6.7 | 7.6 | 8.7 | 9.6 | 16.8 |
| 8 months | 6.3 | 7.0 | 7.9 | 9.0 | 10.0 | 17.5 |
| 9 months | 6.6 | 7.3 | 8.2 | 9.3 | 10.4 | 18.1 |
| 10 months | 6.8 | 7.5 | 8.5 | 9.6 | 10.7 | 18.7 |
| 11 months | 7.0 | 7.7 | 8.7 | 9.9 | 11.0 | 19.2 |
| 12 months | 7.1 | 7.9 | 8.9 | 10.2 | 11.3 | 19.7 |
| 13 months | 7.3 | 8.1 | 9.2 | 10.4 | 11.6 | 20.2 |
| 14 months | 7.5 | 8.3 | 9.4 | 10.7 | 11.9 | 20.7 |
| 15 months | 7.7 | 8.5 | 9.6 | 10.9 | 12.2 | 21.2 |
| 16 months | 7.8 | 8.7 | 9.8 | 11.2 | 12.5 | 21.6 |
| 17 months | 8.0 | 8.8 | 10.0 | 11.4 | 12.7 | 22.1 |
| 18 months | 8.2 | 9.0 | 10.2 | 11.6 | 13.0 | 22.6 |
| 19 months | 8.3 | 9.2 | 10.4 | 11.9 | 13.3 | 23.0 |
| 20 months | 8.5 | 9.4 | 10.6 | 12.1 | 13.5 | 23.5 |
| 21 months | 8.7 | 9.6 | 10.9 | 12.4 | 13.8 | 23.9 |
| 22 months | 8.8 | 9.8 | 11.1 | 12.6 | 14.1 | 24.4 |
| 23 months | 9.0 | 9.9 | 11.3 | 12.8 | 14.3 | 24.8 |
| 24 months | 9.2 | 10.1 | 11.5 | 13.1 | 14.6 | 25.3 |
Boys: average weight and percentiles by month (WHO)
Values in kg at each percentile. The median is the average weight for that age; it is also shown in lb.
| Age | 3th | 15th | Median | 85th | 97th | Median (lb) |
|---|---|---|---|---|---|---|
| Birth | 2.5 | 2.9 | 3.3 | 3.9 | 4.3 | 7.4 |
| 1 month | 3.4 | 3.9 | 4.5 | 5.1 | 5.7 | 9.9 |
| 2 months | 4.4 | 4.9 | 5.6 | 6.3 | 7.0 | 12.3 |
| 3 months | 5.1 | 5.6 | 6.4 | 7.2 | 7.9 | 14.1 |
| 4 months | 5.6 | 6.2 | 7.0 | 7.9 | 8.6 | 15.4 |
| 5 months | 6.1 | 6.7 | 7.5 | 8.4 | 9.2 | 16.6 |
| 6 months | 6.4 | 7.1 | 7.9 | 8.9 | 9.7 | 17.5 |
| 7 months | 6.7 | 7.4 | 8.3 | 9.3 | 10.2 | 18.3 |
| 8 months | 7.0 | 7.7 | 8.6 | 9.6 | 10.5 | 19.0 |
| 9 months | 7.2 | 7.9 | 8.9 | 10.0 | 10.9 | 19.6 |
| 10 months | 7.5 | 8.2 | 9.2 | 10.3 | 11.2 | 20.2 |
| 11 months | 7.7 | 8.4 | 9.4 | 10.5 | 11.5 | 20.8 |
| 12 months | 7.8 | 8.6 | 9.6 | 10.8 | 11.8 | 21.3 |
| 13 months | 8.0 | 8.8 | 9.9 | 11.1 | 12.1 | 21.8 |
| 14 months | 8.2 | 9.0 | 10.1 | 11.3 | 12.4 | 22.3 |
| 15 months | 8.4 | 9.2 | 10.3 | 11.6 | 12.7 | 22.7 |
| 16 months | 8.5 | 9.4 | 10.5 | 11.8 | 12.9 | 23.2 |
| 17 months | 8.7 | 9.6 | 10.7 | 12.0 | 13.2 | 23.7 |
| 18 months | 8.9 | 9.7 | 10.9 | 12.3 | 13.5 | 24.1 |
| 19 months | 9.0 | 9.9 | 11.1 | 12.5 | 13.7 | 24.6 |
| 20 months | 9.2 | 10.1 | 11.3 | 12.7 | 14.0 | 25.0 |
| 21 months | 9.3 | 10.3 | 11.5 | 13.0 | 14.3 | 25.5 |
| 22 months | 9.5 | 10.5 | 11.8 | 13.2 | 14.5 | 25.9 |
| 23 months | 9.7 | 10.6 | 12.0 | 13.4 | 14.8 | 26.3 |
| 24 months | 9.8 | 10.8 | 12.2 | 13.7 | 15.1 | 26.8 |
How to read this chart
A percentile tells you how a measurement compares with other children of the same age and sex. At the 50th percentile (the median), half of children measure more and half measure less. At the 15th percentile, 15 out of 100 children measure less.
Anything between the 3rd and the 97th percentile is within the usual range on the WHO chart. Pediatricians pay more attention to the direction of the curve over several visits than to any single number: a baby who stays near the 15th percentile is usually growing just as steadily as one who stays near the 85th.
Percentiles here come from the official WHO LMS tables, calculated at each whole month. Between months, the calculator interpolates for your baby’s exact age.
Common questions
What is a normal weight for a baby?
On the WHO standard, the 3rd to 97th percentile at 6 months runs from 5.8–9.2 kg for girls and 6.4–9.7 kg for boys. Where your baby sits in that range matters less than whether they keep following their own curve.
How do I find my baby’s weight percentile?
Enter your baby’s date of birth and weight in the calculator on this page. It uses the WHO LMS method, the same one used to draw pediatric growth charts, and also shows the z-score.
When do babies double their birth weight?
Using the WHO medians, girls double their birth weight at about 5 months and boys at about 4 months. Individual babies vary.
Should I use the WHO or the CDC growth chart?
The CDC recommends the WHO growth charts for children under 2 years in the United States, and the CDC charts from age 2. The WHO charts describe how healthy breastfed babies grow in good conditions; the CDC charts describe a reference group of US children.
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Source: WHO Child Growth Standards (WHO Multicentre Growth Reference Study). For information only; not medical advice.