• A map showing Greenland's actual size compared to its Mercator projection portrayal

    On conventional Mercator projection maps, Greenland appears to be similar in size to the continent of Africa, when in reality it has about the same surface area as the African country of Algeria. (Map: James Talmage and Damon Maneice/The True Size Of)

Are you sitting down? The world map you're probably most familiar with has been misleading you in a subtle but important way: many land masses appear either smaller or larger than they actually are. 

Fortunately, a new online map, The True Size Of, is here to set the record straight. The interactive map allows users to search for a country and then compare its actual surface area against a Mercator projection map, one of the most popular and yet most inaccurate maps of our world. 

The problem is that to portray our spherical globe in two-dimensional form, cartographers have to use a "projection," which converts lines of latitude and longitude into locations on a plane. All projections cause some distortion, but the Mercator projection is particularly egregious, exaggerating the size of land masses near the poles, while shrinking land masses near the equator.

For example, Greenland is usually portrayed as roughly the same size as the continent of Africa, but its actual surface area is about 2.1 million square kilometres — less than the African country of Algeria. Conversely, Brazil — the fifth-largest country in the world by surface area — appears to be the same size as the state of Alaska, but as the screenshots below demonstrate, the reality is wildly different. 

James Talmage and Damon Maneice, creators of The True Size Of, say they hope geography teachers will use the map to show their students how big the world really is. 

A comparison of the true size of Alaska and Brazil and their portrayal on a Mercator projection map

On a standard Mercator projection map (left), Alaska and Brazil appear similar in size, but in reality (right), Alaska is a fifth of the size of Brazil. (Map: James Talmage and Damon Maneice/The True Size Of)

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