Baby Percentile Calculator | WHO & CDC Growth Charts 0–24 Months
Calculate your baby's weight, length/height, and head circumference percentiles using official WHO (0–24 months) and CDC growth charts. Plots each measurement on an interactive growth curve and explains what percentile ranges mean in pediatric context.
What Do Percentiles Mean?
A baby at the 50th percentile for weight is heavier than 50% of babies the same age and sex. Being at the 10th or 90th percentile is not inherently better or worse — percentiles simply show where a child falls relative to a reference population. What matters most is consistent growth along any curve, not the absolute percentile value.
WHO vs CDC Growth Charts
This calculator uses WHO (World Health Organization) standards for children 0–36 months. The WHO charts describe how healthy children under ideal conditions grow, while CDC charts are descriptive (based on how US children actually grew). The American Academy of Pediatrics recommends using WHO charts for children under 2 years.
When to Discuss Growth with Your Pediatrician
| Crossing two major percentile lines | Drop from 50th to 10th, or 75th to 25th over time |
| Below 3rd or above 97th percentile | May warrant evaluation — not automatically abnormal |
| Length-for-weight concerns | Very low = undernutrition; very high = overweight risk |
| Head circumference changes | Rapid increase may indicate hydrocephalus; slow = microcephaly |
| No weight gain for 2+ months | Possible failure to thrive — warrants immediate evaluation |
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