ShapefileChoroplethTerracotta theme

Population density by state

Density computed from two columns, population and land area, rather than plotted directly. Deriving a field from the source table is the difference between a map of what you measured and a map of what you meant.

Start an editable copy with this data and your current map styling.

Loading Shapefile data
Census state boundaries. Density is derived from rounded population and area figures, so it is approximate.

What to look at

  • A derived field: people divided by area, computed at import rather than in the spreadsheet.
  • A hot sequential ramp makes the New Jersey to Wyoming contrast impossible to miss.
  • Shapefile input, so a zipped .shp set with a .dbf attribute table imports directly.

Source columns

These fields describe the example data. CSV and Excel use first-row headers; GIS formats store geometry and feature properties. Required geometry depends on the map type.

ColumnTypeExample
statetextNew Jersey
population_millionsnumber9.3
area_thousand_km2number23

Rebuild it with your own data

  1. 1

    Get your Shapefile file ready

    The example fields are state, population_millions, area_thousand_km2. For CSV or Excel, put headers in the first row. GIS files carry geometry and feature properties. Prepare any grid, catchment or route geometry before import.

  2. 2

    Drop it into the studio

    MapCrafter detects the geometry, counts the features, and shows the layers it found.

  3. 3

    Style the imported layer

    Pick which column drives colour, and which drives size or width where relevant.

  4. 4

    Pick a basemap theme

    Terracotta is used here. 15 other basemaps are available, including official OpenFreeMap styles. Switch using Layers & basemap.

  5. 5

    Share or export

    Publish a link, embed the map, or export a PNG at print resolution.

Questions about this example

What file format does this choropleth use?
This example illustrates Shapefile data. The live preview uses GeoJSON geometry. MapCrafter reads Shapefile directly, along with Excel, CSV, KML, KMZ, GPX, GeoJSON, TopoJSON and zipped Shapefile. No conversion step and no desktop software.
What columns does the source data need?
The file used here has 3 columns: state, population_millions, area_thousand_km2. For tabular imports, supply coordinate columns, WKT or GeoJSON geometry, or address columns for an explicit geocoding step. Polygon and line files carry their geometry separately from these attributes.
Can I use my own data with this map type?
Yes. Open the studio, drop in your file, and MapCrafter detects the geometry and applies a starting style. Then style the layer and choose which property drives colour, size or width. The studio can render a point heatmap, but grids, routes and catchment polygons must be prepared before import.
Can I export or share the finished map?
Each map can be published to a short share link, embedded in another page with an iframe, or exported as a print-resolution PNG. The cleaned-up geometry can also be exported as GeoJSON. All of that is available on the free tier.
Where does the data in this example come from?
Census state boundaries. Density is derived from rounded population and area figures, so it is approximate.

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Last updated 2026-10-22