According to a survey from Pew, about 1.5% of all adults in the United States are Catholic converts, amounting to about 4 million individuals total.
“While Catholic converts account for a relatively small share of the country’s adult population,” the report reads, “the number of converts to Catholicism is on par with or larger than the number of Americans who identify with some sizable Protestant groups, including Presbyterians, Episcopalians and Reformed Christians.”
Converts to Catholicism make up about 8% of the total US Catholic population.
Pew also noted that most “religious switching” – leaving one affiliation or converting – happens before the age of 30. “For every adult who becomes a Catholic after having been raised something different, more than eight of those who were raised Catholic no longer identify that way,” the report reads, but that might give the false impression that the overall Catholic population in the United States is shrinking. This is not the case.
Other research notes that from 1965 to 2025, the overall percentage of US adults that are Catholic converts increased 50% and the total Catholic population grew from 44.3 million to to at least 66.3 million, but when accounting for foreign-born individuals living in the United States and identifying as Catholic, the number rises to 73.7 million.
The Pew report adds that about two-thirds of all Catholic converts came from another Christian denomination, and about six in ten came from Protestantism.
About 38% of Catholic converts say they attend Mass weekly, higher than the cradle Catholic population at 28%.
Catholic converts are also more likely to be registered Republicans than cradle Catholics. Overall, registered voters who identify as either Republican or leaning Republican make up 53% of the Catholic population compared to 43% who are Democrat or lean Democrat.
