Low but stable percentile
- Input
- Peso no percentil 10 aos 3, 6 e 9 meses
- Expected output
- Provavelmente típico para o bebê, sem alarme
Consistent growth in the same band usually reflects individual constitution.
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what does baby weight percentile mean
A baby in the 20th weight percentile is not "below the grade". It just means that, among 100 babies of the same age and sex, about 20 weigh the same or less, and 80 weigh more.
Consistent growth in the same band usually reflects individual constitution.
A drop of two or more percentile bands is a more relevant warning sign than the isolated value.
It means that, among 100 babies of the same sex and age in the WHO reference population, about 60 have a value equal to or lower, and 40 have a higher value. It is not a score from 0 to 100: a baby in the 15th percentile can be perfectly healthy, just smaller than most babies of the same age.
Not necessarily. It can indicate a genetically small and healthy child, especially if growth is consistent over time and the parents are also smaller in stature. The pediatrician evaluates the full context.
Not necessarily, but a very large gap between them (for example, weight in the 90th percentile and length in the 10th) may be evaluated with the weight-for-length curve, which exists separately from the weight-for-age and length-for-age curves.
Not directly. For babies born before 37 weeks, the pediatrician typically uses corrected age (calculated from the expected due date, not the birth date) when reading the chart up to 24 months, which avoids labeling as low weight a baby who is simply growing on their own expected timeline.
Small technique variations, such as a fussy baby on the scale or a leg not fully extended when measuring length, plus rounding age to whole months, can shift the calculated percentile by a few units. That is why a pediatrician looks at the trend across several visits rather than a single isolated measurement.
Medical notice: this calculator is educational, based on the WHO growth standards, and does not replace a pediatrician's assessment. A single point outside the typical range is not a diagnosis; what matters clinically is the trend over time.
The data you enter stays only in your browser. We do not save or send these measurements anywhere.