Waffle charts are an underused alternative to pie charts

I was looking at a poster with a pie chart recently. Like this:

There are a lot of criticisms of pie charts, but this was not a terrible example. But I was struck by how awkward that circle looked in a rectangular space.

Again, this was not a particularly bad example. But if the vertical space is smaller...

The unused space problem gets larger and more noticeable.

Let’s changed our cooked goods metaphor. Instead of pie, let’s try a waffle.

Waffle charts are also sometimes called “unit charts.” Like a pie chart, they show part to whole relationships. Unlike pie charts, you tend not to end up with tiny slivers, and there is far less temptation to try rotating it or adding 3-D perspectives.

And you can reconfigure the shape to different proportions. A percentage can be shown three ways and have no straggling units. This provides you with more options to fit your graph to a space.

All of these could be vertically oriented. That is, 25 rows of 4 columns instead of 4 rows of 25 columns shown above.

And if you are okay with rows or columns having a slightly different number, you have even more options.

So now your space might be filled more like this:

There isn’t a button in PowerPoint to make a waffle chart, but a series of squares is very easy to draw in PowerPoint! For that matter, it should be trivial to do in any graphics package. Once you have done it once, you can keep one as a template that you can use repeatedly.

Can you make a waffle chart in Excel? Yes, with qualifications. Chapter 10 of John Schwabish’s book Data Visualization in Excel contains a step by step description of how to turn an Excel spreadsheet into a waffle chat. Turning a spreadsheet into a graphic that can be pasted into a large format conference poster might be a little tricky.

Reference

Schwabish J. 2023. Data Visualization in Excel: A Guide for Beginners, Intermediates, and Wonks. CRC Press. https://doi.org/10.1201/9781003321552