Of people in the world with a religion, 37.7% are Christians, 27.7% are Muslims, 17.9% are Hindus, 14.7% are Buddhists. Together, that’s 98% of the world’s religious population.

I calculated these percentages using data from a report by Pew Research released in 2012.

Now, I should explain a little about how I got that figure for Buddhism. The Pew Research report undercounts Buddhists by artificially splitting respondents from East Asia into separate categories like Buddhist, Daoist, Shintoist, or Folk Religionist.

It must be understood that followers of Daoism, Shinto, and East Asian folk religion are almost always also followers of Buddhism, and can be considered a subset of the Buddhist population. Thus I have included the Pew Research figures for those religions in my figures for Buddhism. That doesn’t make a big difference in the case of Daoism or Shinto, because very few respondents chose those options. (According to the figures from Pew Research, just 0.1% of the world’s population is Daoist, and less than 0.1% are Shintoist.) But Pew does report a significant number of people in China, Taiwan, and Vietnam as identifying with folk religion, and I have included those in my count for Buddhism.

When compared to the “Big Four”, no other religion comes within an order of magnitude to those numbers. Excluding folk religions, the next largest religious group is Sikhism, which makes up just 0.4% of the world’s religious population. Jews make up 0.2% of the world’s religious population. The Baha’i Faith is slightly under 0.1%. Other religions, like Jainism and Zoroastrianism, are so far under 0.1% that they would have to be rounded to zero.