Metro areas sized by population
Proportional circles for the world’s largest metro areas. Symbol area scales with the value, not the radius, which is the difference between a map that communicates magnitude and one that exaggerates it by a factor of four.
Start an editable copy with this data and your current map styling.
What to look at
- Separate latitude and longitude columns are detected and combined into points.
- Symbol size is driven by a field, with a legend that maps diameter back to value.
- Semi-transparent fills keep overlapping symbols readable in dense regions.
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.
| Column | Type | Example |
|---|---|---|
| name | text | Lagos |
| country | text | Nigeria |
| lat | number | 6.5244 |
| lng | number | 3.3792 |
| population | number | 13345000 |
Rebuild it with your own data
- 1
Get your CSV file ready
The example fields are name, country, lat, lng, population. 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
Drop it into the studio
MapCrafter detects the geometry, counts the features, and shows the layers it found.
- 3
Style the imported layer
Pick which column drives colour, and which drives size or width where relevant.
- 4
Pick a basemap theme
Ivory is used here. 15 other basemaps are available, including official OpenFreeMap styles. Switch using Layers & basemap.
- 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 proportional symbol use?
- This example illustrates CSV data. The live preview uses GeoJSON geometry. MapCrafter reads CSV 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 5 columns: name, country, lat, lng, population. 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?
- Real city coordinates from the built-in place table with rounded metro population estimates used for relative sizing only.
More bubble maps examples
Gallery (314)- CSVAir quality stations across EuropeSensor readings on a sequential colour scale, so brighter marks reveal higher simulated measurements. Larger station symbols keep each city cluster visible at a continental scale, while the legend states the numeric intervals used by the colours.
- GeoJSONA sensor network coloured by readingPoint data coloured on a sequential ramp, one marker per station. Sequential colour on symbols works when the markers are large enough to compare; below about eight pixels, size or clustering carries the signal better.
- ExcelJapanese metro areasA dense coastal corridor rendered as proportional symbols over the Midnight theme. Widely varying symbol sizes need a dark, low-contrast basemap so the largest markers do not compete with the map underneath them.
Last updated 2026-10-22