There are two workarounds to create a donut chart in Tableau.  Follow along with the sample packaged workbook found in the Attachments section of this article.

Option 1: Use Two Pie Charts

Step 1: Create a pie chart

1. In Tableau Desktop, connect to Superstore sample data.
2. Under Marks, select the Pie mark type.
3. Drag Segment to Color.
4. Drag Sales to Angle.
5. Drag a second copy of Sales to Label.
6. Resize the pie chart as desired.

Step 2: Switch to the dual-axis chart

1. Select Analysis > Create Calculated Field
2. In the Calculated Field dialog box that opens, do the following, and then click OK:
   1. Name the calculated field. In this example, the calculated field is named "Dummy Axis"
   2. In the formula field, enter the formula: MIN(1)
3. Drag Dummy Axis to Rows.
4. Drag Dummy Axis to Rows again.
5. On Rows, right-click the second instance of Dummy Axis, and then check Dual Axis.

Step 3: Change the second pie chart to a circle

1. At the bottom of the Marks card, click AGG(Dummy Axis) (2).
2. Remove Segment from Color.
3. Remove Sales from Angle.
4. Click Color, and then choose the same color as the background. In this example, click white.
5. Click Size, and then drag the slider to the left to make the circle smaller.
6. Right-click on each of the axes and uncheck Show Header.

Option 2: Use One Pie Chart and an Image File

You can also create a pie chart as in Step 1 above, add it to a dashboard, and place a circular .png image over the middle. See How to Make Donut Charts in Tableau at Tableau A to Z blog for more information. 

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