The Roman Catholic Church is a massive organization, with members in nearly every country numbering over 1 Billion individuals. With such massive numbers and such extensive influence in the world, it is difficult to guess and estimate where tomorrow's Roman Catholics will come from.

I can think of four distinct possibilities:

  1. Most of today's converts are from the missionary work done in lands that have little Christian influence, such as many parts of Asia, those being mostly Hindu, Islam, and Buddhist.

  2. Most of today's converts are from the missionary work done in lands that have much Christian influence, such as Europe or the Americas, which focus on persons not claiming to already be Christian.

  3. Most of today's converts are from other Christian denominations.

  4. Most of today's "converts" are the newborn children raised in the Faith who do not leave it when they become adults.

So I wonder if there are studies that show the numbers for the Roman Catholic Church. Are there studies that can show me how many people convert, and where they are from, and what they believed/followed previously? I would like to see a breakdown of conversion numbers by continent, or country if possible, and which category they fit into. A superb answer would include numbers for those who leave the Faith.

  • 1
    I like how you have converts in quotations with your 4th point - it does make me wonder though, are they really converts if they are born into a family that is Roman Catholic and are raised as such, never leaving the Roman Catholic Church?
    – IndigoGirl
    Sep 4, 2013 at 12:49
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    @IndigoGirl I chose to put it in quotes because they never actually convert. They are born, then they are raised in the Faith and keep the Faith through adulthood. But, yes, that is a big sociological discussion: are your beliefs learned from your parents or not?
    – user3961
    Sep 4, 2013 at 18:26
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    That's what I was commenting on, the fact that they really are not converts. It's like a label that doesn't quite fit. To be honest, not completely. I learned from outside influences such as my grandparents, family friends, my own friends and my own curiosity.
    – IndigoGirl
    Sep 5, 2013 at 18:45

1 Answer 1


From 2000-2008:

Over these nine years, the Catholic presence in the world has grown from 1.045 billion in 2000 to 1.166 billion in 2008, an increase of 11.54%. Considering the statistics in detail, numbers in Africa grew by 33%, in Europe they remained generally stable (an increase of 1.17%), while in Asia they increased by 15.61%, in Oceania by 11.39% and in America by 10.93%. As a percentage of the total population, European Catholics represented 26.8% in 2000 and 24.31% in 2008. In America and Oceania they have remained stable, and increased slightly in Asia.

Source: zenit.org (from the Statistical Yearbook of the Church)

Unfortunately this doesn't help identify the converts' previous religious beliefs, but possibly the Yearbook might have those sort of details.

  • Knowing the religious backgrounds of converts could be very interesting. For example, given what I know about the demographics of France, I imagine that a majority of converts are former Muslims with minorities of former Protestants and Greek Orthodox, but I don't have hard data. Apr 25, 2022 at 16:47

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