How to create a pie chart
A pie chart is useful when you want to show proportional parts of a whole. A pie chart must not feature too many parts as the chart otherwise gets cluttered and hard to read. There is a bit of debate whether a pie chart should show just two, a maximum of three or in some cases up to five parts. But there is consensus that any number above five suggests that a bar chart or column chart is the visualisation to be used.
One reason though why pie charts are popular is that people can understand them at a glance. So in some chases you might well use a pie chart, but for simple comparisons only. Our advice is to use not more than three pies.
Below is an example of a pie chart that makes good use of the part of whole concept: The user can see that the number of people voting to leave the EU in the "Brexit" was only slightly higher than the group which voted for for "remain".
Here are the steps to create a pie chart.
1. Preparing the data
Here is how your spreadsheet should look like:
- One header row
- At least two categorical dimensions
- Comparable measures for each category
The data in your spreadsheet (Excel, Google Sheets, others) should look like the example below.
Don't forget to have names in the header line and make sure to copy them before switching to Datawrapper.
Source: The Electoral Commission
The most important thing you have to keep in mind is that a pie chart always represents a whole, i.e. 100%. Therefore, you can only use data that is based on exclusive values. Making a pie chart of a survey that allows multiple answers will lead to a misleading chart. Use a bar chart instead, but never a pie chart.
Once your dataset looks like the example above, you can copy it. Then paste the data into Datawrapper and click "Upload and continue".
2. Check & Describe
Once you copied your dataset into Datawrapper it should look like this:
Check wether the box "First row as lable" is ticked so that Datawrapper correctly assigns the values to the labels. Datawrapper does this automatically. But you as the user must make sure that the first row actually contains the labels, not already the data. If that is all good, you can move on. If the labels are missing because there were none in the spreadsheet or you simply did not copy them - start over, create a new chart and this time copy the first row with labels.
All done? Great, click on "Proceed" and Datawrapper will take you to the next step.
The chart type to choose here is the " Pie chart". It can happen that the chart appears to small. If that is the case, click, hold, and drag the resize-arrow in the lower right corner of the chart to resize the chart. Experienced users of Datawrapper will know that, but if you just started it is important to know that with the selection of this chart type the options and features available for this chart will change in the sections Refine, Annotate and Design. We cover this in a separate short tutorial found here.