# 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.

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## 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.

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## What the data needs to look like

| **Field** | **Type**                     |
| --------- | ---------------------------- |
| Label     | Nominal: the slice name      |
| Value     | Quantitative: the slice size |

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## A worked example

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

![Pie chart](https://help.gocapable.com/images/att1417674830.svg)

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
```

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## 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.

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## Related

[Donut chartA pie with the middle back.](https://help.gocapable.com/diagrams/donut-chart.html)

[Area chartA total over time, and what makes it up.](https://help.gocapable.com/diagrams/area-chart.html)

[Charts and graphsBack to the chart overview.](https://help.gocapable.com/diagrams/charts-and-graphs.html)

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_Pick the chart for the question, not for the look._