Donut charts are similar to pie charts in that they are used to display different data sections that total up to 100 percent. They are best for comparing a handful of categories at a glance, and they give a good picture of how each category relates to the data as a whole. Donut charts accommodate fewer categories than pie charts because viewers need to be able to see different arc lengths clearly. As such, donut charts are best for visualizing data that’s split into two to five sections.