Islam is the predominant religion in the Middle East, in northern Africa, and in some parts of Asia. Large communities of Muslims are also found in China, the Balkans, and Russia.
Other parts of the world host large Muslim immigrant communities; in Western Europe, for instance, Islam is the second largest religion after Christianity, though it represents less than 5% of the total population.
A demographic study conducted by the Pew Research Center in October 2009 found that there are 1.57 billion Muslims around the world, accounting for roughly 1 in 4 people. The study found more Muslims in Germany than in Lebanon and more in China than in Syria.
Enjoy watching this video that talks about the Muslim demography in the world.