Clearly and Simply

Cartograms in Microsoft Excel

How to create Cartograms in Microsoft Excel

The article Cartograms in Tableau described the limitations of Choropleth Maps under certain circumstances and why Cartograms can sometimes be a viable alternative to color coded maps.

Building upon that, the previous post (Create your own Cartograms in Tableau) provided a Microsoft Excel tool to create the polygons for Cartograms based on your own data. The Excel tool (called Cartogram Data Generator) is based on my VBA implementation of “an algorithm to construct continuous area cartograms” by J. Dougenik, N. Chrisman and D. Niemeyer, published in “Professional Geographer” back in 1985.

With this VBA algorithm and two other techniques previously published here (Faster Choropleth Maps with Microsoft Excel and Create Excel Freeform Shapes from Polygons), we have all modules available to calculate and plot Cartograms directly in a stand-alone Microsoft Excel workbook.

Today’s post describes how to create Cartograms in Microsoft Excel and provides two versions of the Cartogram workbook for free download.

Create your own Cartograms in Tableau

The Cartogram Data Generator: a free Excel Tool to create your own polygon data for plotting Cartograms in Tableau

One of the recent posts showed how Cartograms can be a viable alternative when Choropleth or Filled Maps are stretched to their limits and tell the wrong overall story:

Cartograms in Tableau

The article included a Tableau Public dashboard comparing Filled Maps with Cartograms for the results of the US Presidential Elections since 1900.

Since Tableau does not provide Cartograms as a built-in chart type, the distorted polygons have to be calculated outside of Tableau and then used as a data source to plot the maps using Tableau’s polygon map approach.

Today’s article is the follow-up post. It provides a free and open Microsoft Excel workbook to create Cartogram data with a few mouse clicks: copy in the data and the original polygon points of all regions and let the tool create a ready-to-use data set to plot Cartograms in Tableau.