OpenStreetMap is a global map, and has ways to map and record places of worship (church, mosque, etc). By analyzing the data in OSM, I was able to make a map of the world's religions:

Religions of the world

Based on which religion is most common

Christianity

How common is christianity around the world

How it works

I wrote a programme that splits the world in 0.1° points, and finds the 10 closest places of worships' to that point. The most popular religion "wins" and is used as a colouring for that box.

White or faded areas are places that are far from any place of worship in the OpenStreetMap database, so we shouldn't extrapolate too much for them. Since this is a map of what's in the OSM database, it will be much more accurate in developed world countries than in developing world areas.

Interesting bits

There are some Voodoo and Animism places in Haiti
Note the muslim concentrations in some large Western European cities (Birmingham, etc.)
Japan is an alternating patchwork of Shinto and Buddhi

Future work

There are a few interesting follow on religion maps that could be made:

Look at the christian denominations within Europe
Look at the christian denominations within North America
Look at the Shinto vs. Buddhist within Japan
Rather than looking at the most popular religion, calculate a christian/muslim/etc. score based on how close the nearest one is

Technical details

I have genericised this a custom tool: OSMStatAggregator.

Map Projection

The map is the Robinson Projection, which was used by the National Geographic Society. I dislike the Mercator Projection for distoring land area so far north.

Copyright

The map is based on data from the OpenStreetMap project, and is © OpenStreetMap contributors, and that data is available under the Open Data Commons Open Database License (ODbL).

Religions of the World