About donut charts

As you suspected, donut charts are a lot like pie charts but with a hole. They allow a 2nd set of data to be contained within, and adjacent to, an outer set, as in the figure to the right:

Find a critique of donut charts  here at  Junk Charts. The blog's author turns a donut hole chart into a line and bar chart for us.  You decide.

Here is an effective donut chart that shows web browser market shares very nicely.

Excel's advice on when to use donut charts:

• You have one or more data series that you want to plot.

• None of the values that you want to plot is negative.

• None of the values that you want to plot is a zero (0) value.

• You don't have more than seven categories per data series.

• The categories represent parts of  a whole in each ring of the doughnut chart.