Pie chart

Pie charts work for two or three slices and stop working somewhere around five. People cannot compare angles accurately, which is the whole task a pie chart sets them.

If you need a pie chart, you probably need a sorted bar chart. If the parts genuinely are a whole and there are few of them, this is fine.

#When this is the right chart

• Two or three parts of a clear whole.

• A single percentage split everyone already understands.

• Presentation slides where familiarity beats precision.

#What the data needs to look like

#A worked example

Three slices, which is where a pie chart still works:

The source, which you can paste into a new diagram and edit:

pie showData
  title Where the deploy time goes
  "Test suite" : 420
  "Build" : 180
  "Deploy and smoke test" : 95

#A few things that catch people out

• Above five slices, use a sorted bar chart. Nobody will thank you for a fifteen-slice pie.

• Slices must sum to a meaningful whole. A pie of unrelated numbers is meaningless.

• Include the values, not only the shapes. Reading angles is guesswork.

#Related

Pick the chart for the question, not for the look.