Child Growth Percentile Calculator

Growth percentiles place a child's height, weight, or head circumference on a scale relative to other children of the same age and sex. Pediatricians lean on these rankings to confirm healthy development and to catch potential concerns before they become serious. The number is easiest to read with an example: a child sitting at the 50th percentile for weight weighs more than half of all children their age and sex, and less than the other half.

Two reference standards feed the ranking. CDC and the American Academy of Pediatrics recommend the World Health Organization (WHO) growth standards from birth to age 2 and the Centers for Disease Control and Prevention (CDC) growth charts from ages 2 to 20. A child's measurement is plotted against the appropriate curve, and the percentile is found by interpolating between the nearest data points. In effect, the figure shows where that child falls within the distribution of a large, healthy reference population.

No single reading defines a child's health; the percentile is one data point among many. Because children grow at their own pace, lining one child's curve up against a sibling's or a friend's rarely tells you much. What pediatricians watch for is not a small wobble from one visit to the next but a significant, sustained shift across several measurements, which is the kind of change that tends to call for a closer look.