True size map – compare the real size of countries

Almost every web map, from Google Maps to OpenStreetMap, uses the Web Mercator projection. It keeps shapes and directions right in small areas, which is why it works so well for streets, but it pays for that by enlarging everything far from the equator. At 60° north, the latitude of Oslo, Helsinki and the south of Alaska, lengths are drawn twice as long and areas four times as large as at the equator. Greenland looks as big as Africa, which is fourteen times larger; Canada and Russia look like giants; and Brazil, India and the Democratic Republic of the Congo look smaller than they are. This page lets you see it for yourself. Pick a country from the list, click one on the map or try one of the examples, and drag its coloured outline to a new place. The outline is turned over the globe as a solid shape, never stretched by hand, so the map itself shows how its size changes: Greenland dragged to the equator shrinks to about the size of the Democratic Republic of the Congo, and Brazil dragged to Scandinavia covers half of Europe. Its home outline stays behind as a dashed line. Add up to twelve countries in different colours to compare them side by side, switch on circles of the same real size to see the distortion across the whole map, and copy the share link to show someone else exactly what you laid out.

How to use it

1. Choose a country in the list, click a country on the map, or press one of the examples.
2. Drag the coloured outline to another place on the map, or select the country in the panel and click where its centre should go.
3. Read its real area and how many times bigger or smaller it looks there than at home; add more countries to compare.
4. Copy the share link, or download the moved outlines as GeoJSON or KML for a GIS or Google Earth.

How accurate is it?

How a country is moved without changing its size

A country is not shifted on the flat map, which would keep its drawn size and its error. It is rotated on the globe as a solid shape, the way you would slide a paper cut-out over a globe: first along its own meridian to the new latitude, then around the polar axis to the new longitude, so it stays upright. The rotation is done on the authalic sphere, the sphere with the same area as the WGS84 ellipsoid, so the area on the ellipsoid stays the same to within 0.05 %, which the tests check with GeographicLib for Greenland, Brazil, Australia and India. Only after that is the outline drawn in Web Mercator, which is why it swells or shrinks.

The real areas

The real area in the panel is the geodesic area of the Natural Earth 1:10 million outline of the country, including lakes and, for Greenland and Antarctica, the ice. It is within about 1 % of the official figure for most countries, but official areas differ: the United States counts coastal and inland water and reaches 9.83 million km², while its land outline is 9.46 million km². Disputed areas follow Natural Earth's de facto borders.

How much bigger it looks

"Looks 3.4× as big as at home" compares the area of the outline as drawn on the Mercator map at the new place with the area drawn at home, point by point, not just at the centre. That matters for long countries: Greenland at the equator looks only about 6 % of its size at home, less than the Mercator factor at its centre (73° N) suggests, because its northern tip at 83° N is stretched far more. The stretch factor in the panel is the Mercator scale at the country's centre on the WGS84 ellipsoid.

Good to know

The shape bends as it moves

A country moved north or south does not only grow or shrink: its far eastern and western ends tilt a little, because meridians meet at the poles, and a wide country moved towards a pole fans out at the top. The country's own centre line stays pointing north, and the area stays the same; the change in shape is simply what the same piece of a globe looks like at another latitude.

Near the poles the map runs out

Web Mercator stops at 85.05° north and south, and Antarctica cannot be shown in one piece, so it is left out of the list. A country dragged further than 80° is held at 80°, and any part that would reach beyond 85° is cut at the edge of the map, so the drawing there is smaller than the truth.

Simplified outlines

The outlines come from a 1:50 million world map and are simplified to a few kilometres, so small islands and fjords are missing. That changes the picture very little at this scale, but the outlines are not suitable for measuring a border or a coastline; use the country borders page for that.