Between mid-2010 and mid-
2016, the number of Muslims in
Europe grew considerably
through natural increase alone –
that is, estimated births
outnumbered deaths among
Muslims by more than 2.9
million over that period. But
most of the Muslim population
growth in Europe during the
period (about 60%) was due to
migration: The Muslim
population grew by an estimated
3.5 million from net migration
(i.e., the number of Muslims who
arrived minus the number who
left, including both regular
migrants and refugees).

Over the
same period, there was a
relatively small loss in the
Muslim population due to
religious switching – an
estimated 160,000 more people
switched their religious identity
from Muslim to another religion
(or to no religion) than switched
into Islam from some other religion or no religion – although this had a modest impact compared with births, deaths and migration.

Overall, regardless of religion or immigration status, there were an estimated 7 million migrants to Europe between mid-2010 and mid-2016 (not including 1.7 million asylum seekers who are not expected to have their applications for asylum approved).

But the number of refugees has surged since 2014. During the three-and-a-half-year period from mid-2010 to the end of 2013, about 400,000 refugees (an average of 110,000 per year) arrived in Europe. Between the beginning of 2014 and mid-2016 – a stretch of only two and a half years – roughly three times as many refugees (1.2 million, or about 490,000 annually) came to Europe, as conflicts in Syria, Iraq and Afghanistan continued or intensified.

Of these roughly 1.6 million people who received refugee status in Europe between mid-2010 and mid-2016 (or are expected to have their applications approved in the future), more than three-quarters (78%, or 1.3 million) were estimated to be Muslims.