A pie chart is a circular chart used to represent the relative frequencies of a data set. It is also called a circle chart. These charts are divided into several slices — each representing a group of the whole data set. The following characteristics are typical of pie charts.

• Each slice is drawn using a different color to differentiate the groups.
• The central angle of each group, as well as its area, is proportional to its relative frequency.

A pie chart allows the visualization of each individual data group when compared to the whole. Alone, however, the chart does not give information about the frequency of each group.

Pie charts might also include the relative frequency of each group written as a percentage. It is also possible to include labels to represent each group with matching colors.