When to use a Pie Chart
A pie chart is best used when trying to work out the composition of something. If you have categorical data then using a pie chart would work really well as each slice can represent a different category. A good example of a pie chart can be seen below.
Another good use for a pie chart would be to compare areas of growth within a business such as turnover, profit and exposure.
A pie chart is a circular graph that is broken down into segments (i.e slices of pie). These segments represent each category's contribution to display parts of a whole. So if your data does not represent this then you should choose another chart. Also when there are similar sized categories, it can be difficult to interpret, so keep that in mind. Although they are very aesthetically pleasing and easy interpret and very powerful, so it is no wonder they are the most ubiquitous choice.
Top tip: On a pie chart what is not apparent is the axis, although it does have one. It is in fact the perimeter of the circle that serves as the axis.
It is important to consider the below points when choosing a pie chart to represent your data:
How many data series do you need for your data?
A pie chart only really works well when you only have one set of data.
Are you using any negative values?
If this is the case then you should stay clear of a pie chart as each segment is equal to its value then when totalled equal to the whole, so using negative values can be rather confusing.
What values are you using?
- Useful for displaying data that is classified into nominal or ordinal categories.
- Generally used to show percentage or proportional data.
- Try not use any zero values, as they cannot be represented.
How many categories?
It is best practice to never have any more than 7 categories as it becomes harder for the eye to distinguish relativity of size between each section.
If you want to learn how to easily make a pie chart with ChartBlocks then in our FAQ area we have a step by step guide of how to make charts?