The sunburst chart is great for showing relationships of hierarchical data and their sizes. Each ring corresponds to a level in the hierarchy. A sunburst chart is more advanced than the doughnut chart as it not only shows the sizes but also shows the relationships in the hierarchy.
The data labels make the sunburst chart quickly quite big if you have much data to graph, a smaller sunburst chart hides the data labels. The treemap is a better choice if you want to more easily compare their sizes.
The image above shows the largest city populations in Africa and Asia.
How to build
Select the data set.
Go to tab "Insert" on the ribbon.
Click the "Insert Hierarchy chart" button.
Click the "Sunburst chart" button.
Sort outer ring categories based on value
The sunburst chart will break if you try to sort the data based only on population, you need to have the first hierarchy level sorted and then sort on population. Follow these steps:
Right click on a cell in your data source.
Click on "Sort".
Click on "Custom Sort..."
Sort on the first hierarchy level (Region) and A to Z.
Click "Add Level" button to add another level.
Select "Population" and "Largest to Smallest" in the drop-down lists.