Pie Chart

A pie chart is a way of displaying data in which a circle is divided into segments (or “slices”) that reflect the relative magnitude or frequency of the categories. For example, the world’s population is divided among the continents as in Table 1. In a pie chart based on these data (Figure 1), the segment for Africa would constitute 13.72% of the total world population, that for Asia 60.63%, and so forth.

Pie charts are most often used to display categorical (i.e., nominal) data, and less often ranked or ordinal data. They are never used to show continuous data, for which line charts are the obvious choice. After a brief history of the pie chart, this entry describes variations of and problems with pie charts and ...