Quand utiliser un Donut Chart
You are showing parts of one whole
Revenue by product line, budget by department, traffic by channel. The segments must be mutually exclusive and add up to 100% of something real.
You have a few large categories
Two to five segments is where a donut works. The reader is comparing a small number of clearly different shares, which angles handle perfectly well.
The total is part of the message
The hole gives you a natural place for the headline number — total revenue, total respondents — so the chart carries both the total and its split without extra chrome.
One share is the story
"Nearly two thirds of revenue comes from one product" reads instantly as a ring. A donut is at its best when you want a single proportion to land, not when you want six compared.