Infant Growth Percentile Tracker
Estimate your baby"s growth percentile based on birth weight, current weight, and age.
Uses simplified WHO growth chart data.
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Estimated Growth Percentile
Infant growth percentiles compare your baby"s weight to the WHO growth standards for children of the same age and sex.
Weight-for-age is the most common growth measure in the first year.
When using pounds, the calculator converts to kilograms (1 lb = 0.4536 kg).
When using kilograms, values are used directly.
Simplified WHO median weights (boys, approximate):
| Age | 5th %ile | 50th %ile | 95th %ile |
|---|---|---|---|
| Birth | 2.5 kg (5.5 lb) | 3.3 kg (7.3 lb) | 4.2 kg (9.3 lb) |
| 3 months | 5.0 kg (11 lb) | 6.4 kg (14.1 lb) | 8.0 kg (17.6 lb) |
| 6 months | 6.4 kg (14.1 lb) | 7.9 kg (17.4 lb) | 9.7 kg (21.4 lb) |
| 9 months | 7.2 kg (15.9 lb) | 9.0 kg (19.8 lb) | 11.0 kg (24.3 lb) |
| 12 months | 7.8 kg (17.2 lb) | 9.6 kg (21.2 lb) | 11.8 kg (26 lb) |
This is a simplified estimator. For accurate percentiles, consult your pediatrician who uses full WHO/CDC growth charts.