There were 1.6 billion Muslims in the world as of 2010 – roughly 23% of the global population – according to a Pew Research Center estimate. But while Islam is currently the world’s second-largest religion (after Christianity), it is the fastest-growing major religion. Indeed, if current demographic trends continue, the number of Muslims is expected to exceed the number of Christians by the end of this century.

Although many countries in the Middle East-North Africa region, where the religion originated in the seventh century, are heavily Muslim, the region is home to only about 20% of the world’s Muslims. A majority of the Muslims globally (62%) live in the Asia-Pacific region, including large populations in Indonesia, India, Pakistan, Bangladesh, Iran and Turkey.

Indonesia is currently the country with the world’s largest Muslim population, but Pew Research Center projects that India will have that distinction by the year 2050 (while remaining a majority-Hindu country), with more than 300 million Muslims.