Bar charts have a limitation: It is difficult to see what portion of the total each item comprises. If knowing about a part of the whole is an important consideration, a pie chart is a better choice for showing the same data. A pie chart also may display each category's percentage of the total. Using the same data from the undergraduate expenditures, we get the pie chart shown in Figure 1.
Figure 1.Pie chart presentation of the expenditures of a college undergraduate for the past year.
The parts of the circle (or pie) match in size each category's percentage of the total. The parts of the pie chart are ordered from highest to lowest for easier interpretation of the data. Pie charts work best with only a few categories; too many categories make a pie chart confusing.