Section I. Religious Demography
The U.S. government estimates the total population at 262.8 million (July 2018 estimate). According to the 2010 census, approximately 87 percent of the population is Muslim, 7 percent Protestant, 3 percent Roman Catholic, and 1.5 percent Hindu. Those identifying with other religious groups, including Buddhism, traditional indigenous religions, Confucianism, and other Christian denominations, and those who did not respond to the census question comprise approximately 1.3 percent of the population.
The Muslim population is overwhelmingly Sunni. An estimated one to three million Muslims are Shia. Many smaller Muslim groups exist; estimates put the total number of Ahmadi Muslims at 200,000 to 400,000.
Many religious groups incorporate elements of Islam, Hinduism, and Buddhism, making it difficult to disaggregate the exact number of followers. An estimated 20 million people, primarily in Java, Kalimantan, and Papua, practice various traditional belief systems, often referred to collectively as aliran kepercayaan. There are approximately 400 different aliran kepercayaan communities throughout the archipelago.
There is a Sikh population estimated at between 10,000 and 15,000, with approximately 5,000 in Medan and the rest in Jakarta. There are very small Jewish communities in Jakarta, Manado, Jayapura, and elsewhere. The Baha’i Faith and Falun Dafa (or Falun Gong) communities report thousands of members, but independent estimates are not available. The number of atheists is also unknown, but the group Indonesian Atheists states it has more than 700 members.
The province of Bali is predominantly Hindu, and the provinces of Papua, West Papua, East Nusa Tenggara, and North Sulawesi are predominantly Christian.