Choropleth Map

A choropleth map shades geographic regions in proportion to a data variable, using a color gradient to represent intensity. It is the most common thematic map for showing how a measurement varies across countries or states.

Best for

  • Showing how a metric varies across geographic regions
  • Visualising population density, income, or election results
  • Providing an at-a-glance overview of spatial patterns

Avoid when

  • Small regions are important but invisible at the map scale
  • Data is point-based rather than area-based — use a bubble map
  • Precise numeric comparison is needed — use a bar chart
Alternatives: Bubble Map , Heat Map