What is a pie chart?
A pie chart is a circular graph that visualizes each data segment as a percentage of a whole. The categories should be mutually exclusive so that the sum of their percentages can total 100%. This is what it typically looks like:
When to use a pie chart
As you can see above, a pie chart is best for when you want to compare parts of a whole, especially when there are fewer than 6 categories. Using fewer categories makes it easier for your audience to quickly understand and identify patterns or trends. However, it doesn’t show changes over time.
Here is an example where you can use a pie chart for your business. It shows the percentages of the visitors from different traffic sources.
You can easily tell that more than half of your traffic comes directly from your website. It could mean you are doing a good job attracting visitors to your website. But there are chances that you included visits from your employees.
How to create a pie chart
There are many BI tools you can use to create a pie chart. In this tutorial, we will use Chartio, a BI tool with no SQL knowledge needed, to create a pie chart with the Chartio Demo Source data set. Let’s see how to visualize marketing spend for the quarter in a Pie Chart.
- Expand Marketing, drag & drop Cost to Measures section
- Click the Total sum of Cost tab to rename the label as Cost for clarity and click Ok
- From Marketing, drag & drop Description to Dimensions section
- Click on Table tool, you will see your pie slices in the 1st column and size of them in the 2nd column
- Click on Pie chart tool and now you have a pie chart!
- If you want a Donut Chart (essentially a Pie Chart with an area of the center cut out) with a total number, click on Setting and check Donut Chart and Show total in center checkboxes. Once you finish setting, click Done.
Best practices for using a pie chart
Pie charts are favorable because they are straightforward and visually easy to understand. But having too many categories and labels or using data with a time element involved can wipe out the advantages. That is to say, pie charts work best if you want to display relative proportions of a few categories with nominal or ordinal data.