There are about 1.57 billion Muslims in the world , according to the report . Report by the Pew Center on Religion & Public Life . Huge as the project of mapping the world 's Muslim population is , it is only the first step in a Pew Forum undertaking . Nearly 2 out of 3 of world 's Muslims are in Islam , report says . Roughly 9 of 10 Muslims worldwide are Sunni , report says .
There are about 1.57 billion Muslims in the world , according to the report . Report by the Pew Center on Religion & Public Life . Nearly 2 out of 3 of world 's Muslims are in Islam , report says . Roughly 9 of 10 Muslims worldwide are Sunni , report says .