How many believers are there around the world?

If you think religion belongs to the past and we live in a new age of reason, you need to check out the facts: 84% of the world’s population identifies with a religious group. Members of this demographic are generally younger and produce more children than those who have no religious affiliation, so the world is getting more religious, not less – although there are significant geographical variations.

According to 2015 figures, Christians form the biggest religious group by some margin, with 2.3 billion adherents or 31.2% of the total world population of 7.3 billion. Next come Muslims (1.8 billion, or 24.1%), Hindus (1.1 billion, or 15.1%) and Buddhists (500 million, or 6.9%).

The next category is people who practise folk or traditional religions; there are 400m of them, or 6% of the global total. Adherents of lesser-practised religions, including Sikhism, Baha’i and Jainism, add up to 58m, or well below 1%. There are 14m Jews in the world, about 0.2% of the global population, concentrated in the US and Israel.

Almost all religions have subdivisions. Christians can be Roman Catholic (the biggest group with almost 1.3 billion adherents), Protestants, Eastern Orthodox, Greek Orthodox, Anglican or many other sub-denominations. Muslims might be Sunni (the majority), Shia, Ibadi, Ahmadiyya or Sufi. Hinduism has four main groups: Vaishnavism, Shaivism, Shaktism and Smartism. There are two main traditions in Buddhism – Theravāda and Mahayana, each with subgroups. Jews can be Orthodox (or ultra-Orthodox), Conservative, Reform or belong to smaller groups.

Geography is important in religion. Asia-Pacific is the most populous region in the world, and also the most religious. It is home to 99% of Hindus, 99% of Buddhists, and 90% of those practising folk or traditional religions. The region also hosts 76% of the world’s religiously unaffiliated people, 700m of whom are Chinese