centile chart

a graph with lines showing average measurements of height, weight, and head circumference compared with age and sex, against which the physical development of a child or fetus can be assessed. The lines of growth on the graph are called centiles, and the number of a centile predicts the percentage of individuals who are below that measurement for a given age; for example, the 10th centile means that 10% of the age- and sex-matched population will be smaller and 90% will be bigger. A child or fetus will normally follow a particular centile, but if growth crosses centiles or lies outside the 97th or 3rd centiles, further investigation may be warranted.