A pie chart, a type of circular statistical graphic, is a visual representation of numerical data. It's a simple yet powerful tool that helps to illustrate a proportion of a whole. But what is a pie chart best used for? Let's delve into the various applications and best practices of this widely-used chart type.
Pie charts are particularly useful when you want to show how a whole (100%) is composed of different parts. They are excellent for comparing parts of a whole, as the size of each slice is immediately apparent. However, they are not ideal for showing trends over time or changes between different groups.
When to Use a Pie Chart
Pie charts are best used when you want to emphasize the proportion of a whole. They are excellent for showing market shares, budget allocations, or the composition of a group.
For instance, a pie chart can effectively show the proportion of a company's revenue generated by different products. It can also illustrate the political affiliations of a country's population or the distribution of a city's population by age.
Showing Market Shares
Pie charts are commonly used to show market shares. They can help investors understand the size of a company relative to its competitors or help businesses understand their market position.
For example, a pie chart can show the market share of different smartphone brands. It can also illustrate the market share of different operating systems in the smartphone industry.
Displaying Budget Allocations
Pie charts are also useful for displaying budget allocations. They can help organizations understand where their money is going and how different departments or projects are funded.
For instance, a pie chart can show the allocation of a company's budget to different departments. It can also illustrate the allocation of a government's budget to different sectors, such as education, healthcare, and defense.
Best Practices for Using Pie Charts
While pie charts are a powerful tool, they should be used judiciously. Here are some best practices to keep in mind:
First, keep the number of slices to a minimum. Too many slices can make the chart difficult to read and understand. A good rule of thumb is to keep the number of slices to six or fewer.
Use Clear and Concise Labels
Each slice of the pie should be clearly labeled. The labels should be concise and easy to understand. Avoid using full sentences or complex terms.
For example, instead of "The proportion of the population that is over the age of 65", you could use "Population over 65".
Consider the 3D Effect
While 3D pie charts can look impressive, they can also be misleading. The 3D effect can make some slices appear larger than they actually are. It's generally best to stick with 2D pie charts.
Moreover, avoid using gradients or textures in your pie charts. They can make the chart more difficult to read and understand.
When Not to Use a Pie Chart
While pie charts are useful in many situations, they are not always the best choice. Here are some situations where you might want to consider alternative chart types:
First, pie charts are not ideal for showing trends over time. If you want to show how something changes over time, a line chart or a bar chart would be a better choice.
Comparing Different Groups
Pie charts are not the best choice for comparing different groups. If you want to compare the sizes of different groups, a bar chart or a column chart would be more appropriate.
For example, if you want to compare the sizes of different political parties in different countries, a bar chart would be a better choice than a pie chart.
Showing Small Differences
Pie charts are not the best choice for showing small differences. If the differences between the slices are small, they can be difficult to distinguish on a pie chart.
In such cases, a bar chart or a line chart might be a better choice. These charts can show small differences more clearly than a pie chart.
In conclusion, pie charts are a versatile and powerful tool for illustrating the proportion of a whole. They are best used when you want to emphasize the size of different parts relative to the whole. However, they should be used judiciously, and alternative chart types should be considered in certain situations. By following best practices, you can create effective and engaging pie charts that help to communicate your data clearly and effectively.