The U.S. government estimates the total population at 81.3 million (July 2018 estimate).  According to the Turkish government, 99 percent of the population is Muslim, approximately 77.5 percent of which is Hanafi Sunni.  Representatives of other religious groups estimate their members represent 0.2 percent of the population, while the most recent published surveys suggest approximately 2 percent of the population is atheist.

Alevi foundation leaders estimate Alevis comprise 25 to 31 percent of the population; Pew Research Center reporting indicates five percent of Turkish Muslims state they are Alevis.  The Shia Jafari community estimates its members make up 4 percent of the population.

Non-Muslim religious groups are mostly concentrated in Istanbul and other large cities as well as in the southeast.  Exact figures are not available; however, these groups self-report approximately 90,000 Armenian Apostolic Orthodox Christians (including migrants from Armenia); 25,000 Roman Catholics (including migrants from Africa and the Philippines); and 16,000 Jews.  There are also approximately 25,000 Syrian Orthodox Christians (also known as Syriacs); 15,000 Russian Orthodox Christians (mostly immigrants from Russia who hold residence permits); and 10,000 Baha’is.

Other groups include fewer than 1,000 Yezidis; 5,000 Jehovah’s Witnesses; 7,000 members of Protestant denominations; fewer than 3,000 Chaldean Christians; and up to 2,000 Greek Orthodox Christians.  There also are small, undetermined numbers of Bulgarian Orthodox, Nestorian, Georgian Orthodox, Ukrainian Orthodox, Syriac Catholic, Armenian Catholic, and Maronite Christians.  The Church of Jesus Christ of Latter-day Saints estimates its membership at 300 individuals.