If you have more than 4 or 5 categories, go with a pie chart. If you have between 2 and 4 categories, go with a donut chart.
Why do you use a donut chart vs a pie chart?
This type of chart can help you compare individual categories or dimensions to the larger whole, just like a pie chart, but with a couple of advantages. Donut charts can make it easier for users to compare individual dimensions. Each of the donut arcs has the same width, but a different length.
Which is better pie chart or donut chart?
The pie graph gives a strong and immediate sense of overall proportions, whereas the donut graph leads the reader's eye around the arcs of the circle – and tend to creates more of a narrative. One advantage of the donut graph is that additional information can be displayed at the graph's center.