Sources for Religious Congregations & Membership Data
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The data used in our reports are from four sources:

2010 data were collected by the Association of Statisticians of American Religious Bodies (ASARB) and include statistics for 236 religious groups, providing information on the number of their congregations and adherents within each state and county in the United States. Clifford Grammich, Kirk Hadaway, Richard Houseal, Dale E. Jones, Alexei Krindatch, Richie Stanley and Richard H. Taylor supervised the collection. These data originally appeared in 2010 U.S. Religion Census: Religious Congregations & Membership Study, published by ASARB.

2000 data were collected by ASARB and include statistics for 149 religious groups, including number of churches and adherents. Dale E. Jones, Sherri Doty, Clifford Grammich, James E. Horsch, Richard Houseal, Mac Lynn, John P. Marcum, Kenneth M. Sanchagrin and Richard H. Taylor supervised the collection. These data originally appeared in Religious Congregations & Membership in the United States, 2000, published by the Glenmary Research Center.

1990 data were collected by ASARB and include statistics for 132 religious groups, including number of churches and adherents. Martin B. Bradley, Norman M. Green, Jr., Dale E. Jones, Mac Lynn, and Lou McNeil supervised the collection. These data originally appeared in Churches and Church Membership in the United States, 1990, published by the Glenmary Research Center.

1980 data were collected by the Glenmary Research Center and include statistics for 111 Judeo-Christian church bodies, including number of churches and adherents. Bernard Quinn, Herman Anderson, Martin Bradley, Paul Goetting and Peggy Shriver supervised the collection. These data originally appeared in Churches and Church Membership in the United States, 1980, published by the Glenmary Research Center.

Data from the 2000 Religious Congregations and Membership Study and the 1990, 1980, 1971, and 1952 Church and Church Membership collections can be downloaded free of charge from the ARDA’s data archive.

The 2010 U.S. Religious Census: Religious Congregations & Membership Study will be available for download soon.


Frequently Asked Questions


Were the standards and methods used to collect the 2010 collection the same as those used for 2000 collection?


How do I cite the 2010 U.S. Religion Census?


Who is included in the 2010 U.S. Religion Census?


How do the number of adherents compare to members?


How did you decide if the religious groups should be classified as Evangelical Protestant, Black Protestant, Mainline Protestant, Orthodox, Catholic or other?


How were Catholics counted?


How were black Protestant churches counted?


How were the Jewish estimates computed?


How were the Muslim estimates computed?


How were Buddhist and Hindu groups counted?


How were non-denominational churches counted?


Why do some counties have more adherents than residents?





Were the standards and methods used to collect the 2010 collection the same as those used for 2000 collection?

Overall, the standards and methods remained the same. However, in an effort to better match these standards, some religious bodies changed the way they report their adherents for the 2010 U.S. Religion Census, or were counted differently by Religion Census researchers. These include Amish, Friends, and Jewish groups, the Catholic Church, the Church of Jesus Christ of Latter-day Saints, the United Methodist Church, and non-denominational Christian churches. Changing methodologies in 2010 to better conform to the data collection standards makes a group’s data more comparable to others in 2010, but less comparable to its own collection in 2000. County-level 2000 data using the new methodology are not readily available. ASARB staff has adjusted some 2000 county-level adherent statistics to allow for a more accurate picture of growth and decline. The revised maps and charts are now available online at www.usreligioncensus.org for those who are interested.

One of the most notable changes involves the Church of Jesus Christ of Latter-day Saints. For the 2000 collection, the LDS Church reported a total of 4,224,026 adherents. This total, however, did not include members who, though baptized, were not at the time associated with a specific congregation. A more inclusive count is the 5,208,827 members reported by the Church in its Almanac and to the Yearbook of American and Canadian Churches. For the 2010 collection, the Church reported an adherent total of 6,144,582, a figure more consistent with what it has reported elsewhere.

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How do I cite the 2010 U.S. Religion Census?

2010 U.S. Religion Census: Religious Congregations & Membership Study. Collected by the Association of Statisticians of American Religious Bodies (ASARB) and distributed by the Association of Religion Data Archives (www.theARDA.com).

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Who is included in the 2010 U.S. Religion Census?

The sponsors invited all religious bodies that could be identified as having congregations in the United States to participate. Final totals include information from 236 religious bodies. Participants included 217 Christian denominations, associations or communions (including Latter-day Saints, Messianic Jews and Unitarian/Universalist groups); counts of Jain, Shinto, Sikh, Tao and National Spiritualist Association congregations, and counts of congregations and adherents from Bahá'ís, three Buddhist groupings, four Hindu groupings, four Jewish groupings, Muslims and Zoroastrians. The 236 groups reported 344,894 congregations with 150,686,156 adherents, comprising 48.8 percent of the total U.S. population of 308,745,538 in 2010. As explained below, membership totals were estimated for some religious groups. There were four non-participating religious bodies that reported more than 100,000 members to the Yearbook of American and Canadian Churches, 2010. These groups reported a combined membership of 1.5 million in the Yearbook, which is not reflected in this data collection. Also, the final membership totals for the historically African-American denominations are incomplete counts. Click here for a complete list of groups that participated in the 2010 U.S. Religion Census.

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How do the number of adherents compare to members?

In an effort to achieve comparability of data, the ASARB staff established two major categories for individuals affiliated with a religious body: members and adherents. The ARDA data set contains only adherent totals. Below is a description of the two categories:

MEMBERS: All individuals with full membership status. For many groups, especially Christian groups practicing adult baptism, full membership status is reserved for adults.

TOTAL ADHERENTS: All members, including full members, their children and the estimated number of other participants who are not considered members; for example, the “baptized,” “those not confirmed,” “those not eligible for Communion,” “those regularly attending services,” and the like.

Of the 236 reporting groups, 49 reported members and adherents; 37 reported adherents only; 63 reported members only; four suggested a method for estimating adherents without reporting members; and 83 reported only congregation locations. Of the 63 that reported members only, four suggested their own adherent estimating processes, which we used to calculate adherents for them. For those 59 groups that reported members but did not report adherents nor suggest a method for computing them, we estimated total adherents for each county by dividing membership by the population at least 14 years of age and then applied this percentage to the Census 2010 100-percent count for the county.

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How did you decide if the religious groups should be classified as Evangelical Protestant, Black Protestant, Mainline Protestant, Orthodox, Catholic or other?

We relied on several sources. We began with an article co-authored by Brian Steensland, Jerry Park, Mark Regnerus, Lynn Robinson, Bradford Wilcox and Robert Woodberry entitled "The Measure of American Religion: Toward Improving the State of the Art," published in Social Forces (2000, 79: 291-318). The authors justify the major categories we use and classify most of the groups that participated in the 2010 U.S. Religion Census. When groups were not included in their classification, we classified them based on information given in J. Gordon Melton’s Encyclopedia of American Religions (7th edition) and Frank S. Mead and Samuel S. Hill’s Handbook of Denominations in the United States (12th edition). Click on the following links to see a list of groups included in each category: Evangelical Protestant, Black Protestant, Mainline Protestant, Orthodox, Catholic or other groups.

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How were Catholics counted?

For the 2010 study, each diocese was asked to provide, by parish or mission, their number of registered households, registered individuals, infant baptisms within the past year, deaths within the past year, and weekly attendance. This was part of an effort to provide a more congregational-based definition comparable to those of other religious bodies in the study. Put another way, the number of "adherents" is roughly equivalent to those who are known in some way to each parish or mission.

Altogether, this work enumerated nearly 59 million Catholics known in some way to each parish or mission in the United States. This number is substantially below two common measures of the Catholic population in the United States: survey data and The Official Catholic Directory (OCD). First, national surveys suggest that over 75 million Americans self-identify as Catholic. However, only 20 percent of respondents on the 2010 General Social Survey (GSS) were Catholics who attend at least once a year. When applied to the population as a whole, the estimated 62 million Catholics who attend at least once a year is reasonably close to the 59 million counted in the 2010 U.S. Religious Census. Second, The Official Catholic Directory (OCD) for 2010 indicated a Catholic population of 65,581,808 in the 50 states and District of Columbia. Yet there is reason to believe that the means used to generate the OCD number varies by diocese, with some dioceses relying on survey estimates of the Catholic population rather than parish-level statistics. For more information on the Catholic count, visit http://www.glenmary.org/rcms2010.

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How were black Protestant churches counted?

For the 2010 U.S. Religion Census, researchers obtained mailing lists for the eight largest historically African-American denominations: the African Methodist Episcopal Church; the African Methodist Episcopal Zion Church; the Christian Methodist Episcopal Church; the Church of God in Christ; the National Baptist Convention of America, Inc.; the National Baptist Convention, USA, Inc.; the National Missionary Baptist Convention, Inc.; and the Progressive National Baptist Convention, Inc. The reported membership totals on the address lists represented less than 50 percent of any of these groups’ churches or members as reported in the Yearbook of American and Canadian Churches, 2010. However, since the available locations did represent nearly four million people associated with specific religious congregations, the researchers decided to include these data in the 2010 Religion Census regardless of whether additional information could be obtained. Further efforts were made to gather denominational statistics. Preliminary results were shared with the groups, but none were able to supply further information. However, three groups did have online church locators, so additional congregation locations were identified for the African Methodist Episcopal Church, African Methodist Episcopal Zion Church and Christian Methodist Episcopal Church. For each congregation located in this way, a membership of 100 was assigned. This represented the modal size of Protestant churches that were reported to the data collection office.

These methods yielded figures that are significantly lower than those reported by the denominations in the Yearbook of American and Canadian Churches, 2010. For example, the U.S. Religion Census includes roughly the same number of congregations belonging to the African Methodist Episcopal Church, but only about one-third of the membership total reported in the Yearbook. For other groups, congregation counts range from 11 percent to 50 percent of reported numbers in the Yearbook, and membership figures are from 7 percent to 28 percent of reported amounts. An adherent formula was used to account for children likely to be associated with each church in addition to adult members. The result is 4,877,067 adherents identified as part of eight historically African American denominations in the United States in 2010. Additionally, three smaller church bodies that had online directories available are described as predominantly African American: Church of Our Lord Jesus Christ of the Apostolic Faith, Inc.; Cumberland Presbyterian Church in America; and United Holy Church of America, Inc. No adherent information was available, so only the locations are included in this study.

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How were the Jewish estimates computed?

The congregational arms of the Conservative (United Synagogue for Conservative Judaism), Reconstructionist (Jewish Reconstructionist Federation) and Reform (Union for Reform Judaism) movements provided the ASARB with lists of their synagogues and exact membership totals (or estimates) for each congregation. For Orthodox synagogues, the main national congregational body, the Union of Orthodox Jewish Congregations (Orthodox Union or OU), provided a list of its synagogues and membership totals. In addition, the website for the National Council of Young Israel lists the names and locations of all Young Israel congregations, an additional source of Orthodox congregations. In addition, researchers consulted the websites of every Jewish Federation in the United States to check for other Orthodox congregations not otherwise found and we consulted a variety of other local and national websites catering to the Orthodox community.

Jewish congregations record their size in terms of "member units" or entire households who pay membership dues. To estimate the number of adherents for each Jewish denomination the number of its households was multiplied by the mean number of its household members (Jewish or not) derived from the 2001 National Jewish Population Survey. The resulting estimate for the four groups combined is 2,256,584 adherents. Note that this is significantly lower than the single estimate of 6,141,325 Jewish adherents in 2000. By comparison, 1.8 percent of General Social Survey respondents self-identified as Jewish in 2010, compared with 2.2 percent in 2000. Thus, the discrepancy likely reflects a change in methodology as well as real decline.

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How were the Muslim estimates computed?

An initial mosque estimate was compiled from the list in the 2000 Masjid Study and three online sources: 1) Muslim Guide, (2) Islamic Finder, and (3) Salatomatic. Local Muslims were contacted to verify information on existing mosques and identify mosques not on our list. Most local Muslims were representatives of local chapters of the Council on American-Islamic Relations (CAIR). The Islamic Shura Council of Southern California also assisted. In New York City, the Center for American Muslim Research and Information helped. Based on these efforts we identified a little over 1,900 mosques. Interviewers conducted a phone interview with mosque leaders and were asked to modify the existing list as they located mosque leaders. Through this process the original list was expanded to its final number of 2,106 mosques.

Ihsan Bagby, Associate Professor at the University of Kentucky, provided location information for each of these mosques to the U.S. Religion Census data collection office and relied on survey information to estimate a total Muslim population within each state. The U.S. Religion Census staff then used Bagby’s state-by-state figures to estimate adherents and attendance for each mosque. For surveyed mosques, the reported adherent and attendance counts were used. For those not surveyed, the remaining state Muslim counts were assigned proportionately, with larger estimates for those mosques within larger metropolitan areas. Totals were then aggregated to the county level.

A total of 2,106 mosques were identified, representing a 74 percent increase over the 1,209 counted in 2000. Though the increase can be attributed partly to improved web sites and data collection, it also reflects real growth in the Muslim population. 26 percent of all the mosques studied were established between 2000 and 2011.

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How were Buddhist and Hindu groups counted?

J. Gordon Melton provided the Religion Census data collection office with a list of 215 Buddhist groups in 2,854 locations. Constance A. Jones and J. Gordon Melton provided a list of 127 Hindu groups with 1,625 locations. In most cases, a total number of persons associated with each group was included. The number of persons associated with specific locations was often available. For groups or locations without identified totals, estimates were made based upon similar groups or locations. After these allocations, the total numbers of adherents reported in the earlier tables may differ slightly from the figures originally reported in the accompanying text.

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How were non-denominational churches counted?

Over the past several years, Scott Thumma, Professor of Sociology of Religion at the Hartford Institute for Religion Research, has been collecting non-denominational church lists available on the Internet. To this list were added eight additional listings of non-denominational congregations, house churches, megachurches and independent networks of churches that were collected on the Web and privately during 2009-2010. Additionally, three purchased mailing lists of independent and non-denominational Christian congregations were added to the database. After all these lists were merged together, the database was then screened for duplicates, incorrect entries, and non-church listings.

Following this effort, a team of six temporary staff persons spent more than 1,000 hours culling the web to attempt to verify the status of these congregations. Every church in the database was looked up on Google and in the online Yellow Pages to confirm if it existed and if it was independent/nondenominational. Every church was emailed and/or called in order to further confirm its independent/non-denominational status, membership and attendance. Additionally, one of the staff members spoke Spanish and established contact with the obviously Hispanic/Latino churches in the listing. Approximately 30 percent responded to the request and verified their information. While engaged in this research, the staff found additional church lists from the websites of newspapers, towns and counties that added new independent and non-denominational churches. They then attempted to confirm the information on these churches using the above method. The end result was a database that contained more than 50,000 potential entries. More than 15,000 were removed due to uncertainty about their existence, size, non-denominational status or being a part of the Vineyard Christian Fellowship or Calvary Chapel networks (which are listed separately in the 2010 U.S. Religion Census). The resulting 35,496 congregations are the best estimate of the independent and non-denominational churches in the United States.

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Why do some counties have more adherents than residents?

In some counties, adherent totals exceed the population as counted by the U.S. Census. Possible explanations include U.S. Census undercount, church membership overcount, and individuals’ county of residence differing from county of church membership.

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