Donut chart

A donut chart is a pie chart with a hole, and the hole is useful: it gives you somewhere to put the total, which is often the number the reader actually wants.

Every limitation of a pie chart applies. The hole does not fix the angle-reading problem.

#When this is the right chart

• Part-to-whole with a total worth showing in the middle.

• Dashboards where the shape is a familiar visual anchor.

• The same two or three categories a pie would handle.

#What the data needs to look like

#A worked example

A donut, with the inner radius doing the work:

The source, which you can paste into a new diagram and edit:

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "description": "Licences by type",
  "width": 280,
  "height": 280,
  "data": {"values": [
    {"type": "Assigned", "count": 184},
    {"type": "Available", "count": 46},
    {"type": "Pending removal", "count": 20}
  ]},
  "mark": {"type": "arc", "innerRadius": 70},
  "encoding": {
    "theta": {"field": "count", "type": "quantitative"},
    "color": {"field": "type", "type": "nominal", "title": "Licences"}
  }
}

#A few things that catch people out

• The hole is for the total. Leaving it empty wastes the only advantage over a pie.

• Three or four categories at most.

• Order the slices deliberately; arbitrary order makes comparison harder still.

#Related

Pick the chart for the question, not for the look.