Part-to-whole
Part to whole relationships
To show:
- ratio
- percentage
- proportion
- share
- breakdown
- make up
- hierarchy
Bar charts and pie charts should be used to show part to whole relationships.
Pie charts should only be used when there are less than six categories, otherwise use a bar chart or, if appropriate, combine categories.
Rank the categories in a pie chart and start the first segment at the 12 o’clock position.
Segments of a pie chart must sum to 100%. If the categories do not sum to a meaningful whole, do not use a pie chart. Where appropriate categories can be combined to highlight a certain message but should never be removed.
Example of pie chart ranked by size of category
All main categories included
Religion categories combined
Example of incorrect use of pie chart with categories removed
No religion and not stated categories removed
If no categories are dominant use a bar chart to illustrate your data.
Example of bar chart where no categories are noticeably dominant
Example of incorrect use of pie chart where no categories are dominant
Multiple part to whole
Use bars to enable comparisons to be made across multiple part to whole charts.
Example of bar chart used to compare multiple part to whole
To enable comparisons within sub-categories
To enable comparisons across sub-categories
