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Calculating how many people live in a given hemisphere is relatively straightforward, and graphing population distribution is a fun activity for a Sunday afternoon. But even after all that math, there are still so many hemispheres unexplored!

This map is the result of a rather staggering amount of calculation. For every point on earth, I've calculated the percent of all humans that live on the half of the globe centered on that point. (This is the same as calculating how many people live within 10,000 kilometers.*) On land, the values range from a high of 92.9% (the Human Hemisphere) to a low of 8.1% on the Antipodes Islands off the coast of New Zealand.

What's perhaps most remarkable here is how almost all of Eurasia is above 80 percent, and a good chunk of Europe is above 92 percent. The center of the Human Hemisphere is a unique point, but there are plenty of places nearby that are almost as special. Given the distribution of land and people around the world, this large plateau of high values makes perfect sense, but it's still striking.



Data from GRUMP, the Global Rural-Urban Mapping Project. Calculations done with ArcGIS.

* Since the meter was originally defined as one ten-millionth of the distance from the North Pole to the equator, any hemisphere has a radius of roughly 10,000 kilometers. But because of errors in the original surveys for the meter, the actual value is closer to 10,010 kilometers; because of the ellipsoidal shape of the earth it also varies by latitude.