Why maps lie about size

On many world maps, Greenland looks as big as Africa. How the Mercator projection warps area, and how DemiSemi draws its countries and states.

Greenland is not the size of Africa

On many world maps, Greenland looks almost as big as Africa. In reality, Africa is about fourteen times larger: roughly 11.7 million square miles, compared with about 836,000 for Greenland.

The culprit has a name: the Mercator projection, which is still everywhere, including on many online maps.

Why Mercator inflates the far north and south

Gerardus Mercator published his map in 1569 for sailors. It preserves angles: a route that keeps the same compass heading shows up as a straight line, which is exactly what a navigator wants.

The tradeoff is that the farther you get from the equator, the more land gets blown up. At 60 degrees north, roughly the latitude of Anchorage, Oslo or the southern tip of Greenland, distances are doubled and areas are quadrupled. Near the poles, the stretching becomes infinite.

No flat map can keep everything

You can’t flatten a sphere without distorting it. Carl Friedrich Gauss proved that in the 19th century. So every map projection makes a choice: some keep angles, some keep distances from one point, some keep areas. None keeps them all.

Maps that get area right

Luckily, there are equal-area projections that keep sizes honest. The Gall–Peters projection, described by James Gall in 1855 and championed by Arno Peters in the 1970s, stirred up controversy because it stretches Africa and South America. The oval Mollweide projection is a favorite for world maps of data. And the newer Equal Earth projection, introduced in 2018, tries to keep the continents looking familiar.

They all distort shapes, especially far from their center. That’s the price of getting areas right.

DemiSemi’s choice: area

In a game about equal halves, area is the only thing that matters. So DemiSemi’s countries, islands, lakes, regions and states are drawn with an equal-area projection, the Lambert azimuthal equal-area projection, centered on each shape to keep its outline as true as possible.

The result: when you split a state that stretches north to south, like California, 50/50 on screen, each half really is half the land. On a Mercator map, the northern half would look bigger than it actually is.

Simplified, never rigged

The outlines come from Natural Earth, a free, public domain map database. They’re simplified so they stay readable on a phone: tiny islands and super-fine details are dropped.

Your score is computed on the shape you see, not on the real border. What you see is exactly what gets measured.