True Size MapD3 · TopoJSON · SVG
True Size World Map
Greenland can look nearly as large as Africa on a wall map, yet Africa has almost fourteen times the surface area. Move northern countries toward the equator to separate their measured area from the size Mercator makes them appear.
Interactive Mercator map
Move the comparison set
Drag any coloured country north or south. The map reports the projection's apparent scale at the new latitude.
No countries selected yet.
Try moving Greenland toward DR Congo to compare the contrast.
One more perspective
Keep exploring the scale
Every toy changes one assumption. Try another and see what moves.
Area before appearance
Why Greenland looks as large as Africa
Mercator stretches the world more with every degree away from the equator. The familiar result makes Greenland loom over the North Atlantic and widens Russia and Canada. Their geography has not grown. The projection has.
Put Greenland over equatorial Africa
- Select Greenland and drag its colored outline south toward the equator.
- Place it over central Africa while leaving the base map visible.
- Read the latitude and scale factor beside the fixed area value.
- Try Russia next, then reset both countries to their original positions.
Area does not follow screen pixels
The number of colored pixels changes as a country moves. The area label does not. That contrast is the point: a projected shape can expand on screen even though the land it represents still covers the same number of square kilometres.
The scale grows as one divided by cosine latitude
Mercator is conformal. Near any single point it keeps angles intact, which is why a compass bearing can be drawn as a straight line. The cost is a scale factor of 1 divided by the cosine of latitude. At the equator, cosine is 1 and the factor is 1. At 60 degrees north, cosine is 0.5, so distances are drawn about twice their equatorial scale. Area expands in two directions, making the local area inflation roughly fourfold. At 80 degrees, the distance factor is about 5.8 and the local area factor is more than 33.
Greenland spans a large range of latitudes, so one factor cannot describe every part of it. Still, its high position explains the visual trick. Moving its outline toward the equator makes Mercator redraw that same spherical geometry where the scale factor is smaller. Africa straddles the equator and receives far less inflation through its middle. A Mercator map can therefore make the two outlines look comparable even though their measured areas are nowhere close.
Real area comparisons
The United Nations reports Africa's surface area as 29.65 million km², while the CIA World Factbook lists Greenland at 2.166 million km². Russia is another useful check: its 17.10 million km² is about 1.74 times the United States' 9.83 million km², not the overwhelming gap suggested by many world maps. Canada and the United States are closer still at 9.98 and 9.83 million km². Moving both to similar latitudes removes much of the visual advantage Canada gets from reaching farther north.
Data and method
Country outlines come from Natural Earth's 1:110 million Admin 0 dataset. The map rotates each selected geometry across a sphere, then draws it again with a Mercator projection. It does not resize the stored area when the outline moves. The listed totals include both land and inland water where the reference source reports total area, so they should not be mixed with land-only figures. Small islands and detailed coastlines are simplified at this map scale. The multiplier shown beside a country is an approximation based on its central latitude. A large country crosses many latitudes, so its northern and southern edges do not share one exact scale factor. Treat that number as an explanation of the projection, not a new measurement of the country. The square-kilometre total is the quantity to use for direct comparisons.
Sources: UNData Africa profile, CIA World Factbook Greenland summary, CIA area comparison table, and Natural Earth Admin 0 countries.
Check a specific pair
Questions about true-size world maps
What is a true size world map?
It is a comparison that keeps each country's measured area fixed while showing how a projection changes its screen size. Moving an outline to another latitude exposes the gap between real area and Mercator appearance.
Is Greenland really as big as Africa?
No. Greenland covers about 2.17 million square kilometres, while Africa covers about 29.65 million. Africa is roughly 13.7 times larger by surface area.
Why does Mercator make northern countries look larger?
Mercator's scale factor rises with latitude. It is 1 at the equator, about 2 at 60 degrees, and about 5.8 at 80 degrees, so shapes near the poles occupy far more map space.
Does a country change area when I drag it?
No. Its stored square-kilometre value stays fixed. The outline is moved across a sphere and projected again, which changes its displayed size but not the amount of land and water it represents.
The country outline moves on a sphere before the map projects it again. Its stored area never changes.