What is the Pie Chart or Pie Graph ?

The best way to understand pie charts is to look at some examples of pie charts.

Click on any of these pie charts included in SmartDraw and edit them:

In addition to the quick-start templates, SmartDraw includes dozens of completed chart examples for every type of chart

Open one that is most similar to your project, and easily edit the data by either importing from Excel or simply dragging the bars, lines, or pie slices.

An introduction to pie charts and how they are used to illustrate data.

This guide explains what a pie chart is, outlines the types of data that can be presented using a pie chart and provides some design tips to ensure that when you use pie charts to present data they are clear and easy to interpret.

For a printer-friendly PDF version of this guide, click here

A pie chart is a circular graph that shows the relative contribution that different categories contribute to an overall total.

A wedge of the circle represents each category’s contribution, such that the graph resembles a pie that has been cut into different sized slices ...

Every 1% contribution that a category contributes to the total corresponds to a slice with an angle of 3.6 degrees.

Pie charts are a visual way of displaying data that might otherwise be given in a small table.

Pie charts are useful for displaying data that are classified into nominal or ordinal categories.

Nominal data are categorised according to descriptive or qualitative information such as county of birth or type of pet owned. Ordinal data are similar but the different categories can also be ranked, for example in a survey people may be asked to say whether they classed something as very poor, poor, fair, good, very good.

Pie charts are good for displaying data for around 6 categories or fewer. When there are more categories it is difficult for the eye to distinguish between the relative sizes of the different sectors and so the chart becomes difficult to interpret.

Pie charts provide a good visual representation of the data when the categories show some variation in size.

When there are several similar-sized categories, a pie chart can end up looking cluttered and it may be difficult to interpret the data.

In such cases consider whether a table would present the information more effectively.

It is usual for the different sectors of the pie chart to be arranged clockwise in order of magnitude.

If there is a slice that does not contain a unique category of data but summarises several, for example “other types” or “other answers”, then even if it is not the smallest category it is usual to display it last in order that it does not detract from the named categories of interest

It is helpful to colour or shade the different slices so that they grade from dark to light tones as you move from the first to the last slice.

Two or more pie charts can be used to compare two sets of data where the categories are the same or similar but there is a change in another variable, such as time or age.

In such cases it is helpful to maintain the same ordering and colouring of slices in the second pie chart as the first in order to facilitate comparison.

This may mean that in the second pie chart the slices are no longer presented in order of magnitude.

If the two charts represent different sized totals show this by making the areas of the pie chart proportional to the totals they each represent.

Avoid design elements that detract from the message you are trying to convey such as 3D effects and exploding slices