[Excel] How to make a bubble heatmap

Excel can’t encode color gradients, but you can use bubble size to create a passable heatmap.

A bubble heatmap in Excel
A bubble heatmap in Excel.

Design notes

  • Much of the effectiveness of heatmaps resides on how the categorical axes are sorted. Try to sort them (manually, if needed) in a way that similarly sized bubbles are clustered together.
  • Check for outliers in the variable you use for bubble size
  • To display the center of the bubble, add the series twice, but use a small and fixed value for bubble size.
  • Check the aspect ratio.
  • Reduce opacity to avoid occlusion (larger bubbles hiding smaller ones).
  • Show bubble outline using a darker color.



Real-world example