Mega Churches: How Big? More than 1.7 million Protestants in the U.S. now attend mega-churches (churches that have a weekly attendance of 2,000 plus). That’s out of a pool of 105 to 111 million people who attend Christian churches weekly. Since 1970, the number of mega-churches in the U.S. has risen from 10 to over 470 in ’98. (Your Church 7-8/99)