iso3, country, gdp_2025_billion_usd,
rank. Values run from $300 billion
(Kazakhstan) to $30.6 trillion (United States), a
100-fold range; together they total $109.7 trillion,
and the U.S. and China alone hold 46% of it.On the log-spaced classes every class is used and economies an order of magnitude apart look different, at the cost that each step means about twice as much; rather than “5 trillion more”. Scroll or pinch to zoom, drag to pan, click to keep a country selected.
Area represents GDP. Each of the 50 economies covers a share of the map equal to its share of their combined $109.7 trillion.
A contiguous diffusion cartogram (Gastner & Newman, 2004) where every economy is within 4.2% of its target area and 46 of 50 are within 1%. Hatched countries have no GDP value: they are kept so the map stays connected and together hold a fixed placeholder 10% of the area, split by land area, so their size is not GDP.
| Rank | Economy | GDP ($B) | Share of top-50 GDP | Share of land | Share of cartogram | Cartogram ÷ land |
|---|
On the choropleth the eye goes first to land: Russia and Canada cover more of the map than the dark United States and China, Brazil and Australia nearly as much, though Russia's economy is a twelfth of America's. On the cartogram the U.S. (25% of the area) and China (16%) dominate, followed by Germany, Japan, India and the United Kingdom.
Small, rich economies grow most: the Netherlands ×40, Taiwan and Switzerland ×27, South Korea ×21, Britain ×18, and Singapore, invisible on the choropleth, ends up larger than Malaysia. Kazakhstan (×0.1), Russia (×0.2), Canada, Australia and Brazil (×0.3) shrink.
The choropleth preserves position, shape, size and adjacency, so it suits locating a country, seeing regional patterns (dense mid-blue across Europe and East Asia, almost all of Africa without data) and reading a value class. But colour is read only coarsely: $2.3 and $2.5 trillion look identical, and big pale countries outweigh small dark ones.
The cartogram keeps neighbours and rough position but distorts shape, size and distance: Africa and Central Asia nearly vanish while Europe swells. It suits magnitude tasks, such as comparing totals or seeing that Germany alone (4.1% of the map) outweighs Brazil, Argentina, Colombia, Chile and Peru together (3.3%). Moving GDP from colour to area turns it from a label on the land into the land itself; concentration becomes visible, at the cost of recognisability.
Projection. Both maps use Equal Earth
(d3.geoEqualEarth), an equal-area projection, so on the
choropleth a country's size is its true land area, and the cartogram
starts from true areas rather than Mercator's inflated Canada and
Russia. The choropleth is drawn with
d3.geoPath().projection(projection); the cartogram's
coordinates are already planar, so it is drawn with
d3.geoPath() and a fitted d3.geoIdentity().
Cartogram. GDP is spread over a 1024×512 grid as a density and allowed to diffuse until it is uniform; every vertex moves with the flow, to ensure borders never cross with each other. Eight passes bring every economy within 4.2% of its target area. A first attempt with the rubber-sheet algorithm of Dougenik et al. (1985), which topogram uses, left France at 13% of its target. The cartogram file keeps every vertex of the original, which is what makes the land-to-GDP morph possible.
Colour. One blue sequential ramp, light to dark, for GDP on the choropleth. The cartogram uses a single flat blue so that area is its only GDP channel, with names printed where they fit. Missing data is a hatched neutral grey in both maps, so it cannot be read as the lightest GDP class.