A nested pie chart stacks two or more concentric pie rings on one chart, allowing hierarchical comparison. The inner ring typically shows top-level categories while the outer ring breaks each category into sub-segments.
Solar System Planets: Type (Inner Ring) → Individual (Outer Ring)
Best for
- Displaying hierarchical part-to-whole relationships
- Comparing a category's overall share with its sub-breakdowns
- Compact two-level proportional views
Avoid when
- There are too many sub-categories — labels become unreadable
- The hierarchy has more than two levels — use a sunburst instead
- Precise comparison between sub-segments is required