Pie chart

A pie chart (or a circle chart) is a circular statistical graphic which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice (and consequently its central angle and area) is proportional to the quantity it represents. While it is named for its resemblance to a pie which has been sliced, there are variations on the way it can be presented. The earliest known pie chart is generally credited to William Playfair's Statistical Breviary of 1801.^[1][2]

Pie charts are very widely used in the business world and the mass media.^[3] However, they have been criticized,^[4] and many experts recommend avoiding them,^[5][6][7][8] as research has shown it is more difficult to make simple comparisons such as the size of different sections of a given pie chart, or to compare data across different pie charts. Some research has shown pie charts perform well for comparing complex combinations of sections (e.g., "A + B vs. C + D").^[9] Commonly recommended alternatives to pie charts in most cases include bar charts, box plots, and dot plots.