U.S. Religion Census: Information on Data Sources
The data used in our Religion Membership Reports are from five sources:
The 2020 data were collected by the Association of Statisticians of American Religious Bodies (ASARB) and include data for 372 religious bodies or groups. Of these, the ASARB was able to gather data on congregations and adherents for 217 and on congregations only for 155. Clifford Grammich, Erica Dollhopf, Mary Gautier, Richard Houseal, Dale E. Jones, Alexei Krindatch, Richie Stanley, and Scott Thumma supervised the collection. These data originally appeared on https://www.usreligioncensus.org/.
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 2010 Religious Congregations and Membership Study and the 2000, 1990, 1980, 1971, and 1952 Church and Church Membership collections can be downloaded free of charge from the ARDA’s data archive.
Frequently Asked Questions
Were the standards and methods used to collect the 2020 data the same as those used for 2010?
How do I cite the 2020 U.S. Religion Census?
Who is included in the 2020 U.S. Religion Census?
What are adherents?
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 2020 data the same as those used for 2010?
Overall, the standards and methods remained the same. The U.S. Religion Census relies to the extent possible on data that religious bodies report themselves. Over time, the standards and methods may acquire greater precision, meaning that exact methods for a specific group may change over time. Users wishing to understand more about exact methods over time should consult the appendices in the volumes cited above as well as the methods material posted on the U.S. Religion Census website. Users may also contact
How do I cite the 2020 U.S. Religion Census?
Clifford A. Grammich, Erica Dollhopf, Mary Gautier, Richard Houseal, Dale E. Jones, Alexei Krindatch, Richie Stanley, and Scott Thumma. 2022. 2020 U.S. Religion Census: Religious Congregations & Adherents Study. Association of Statisticians of American Religious Bodies.
Who is included in the 2020 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 372 religious bodies. Participants included 354 Christian denominations, associations, or communions (including Latter-day Saints, Messianic Jews, Unitarian/Universalist, and non-denominational groups); counts of Jain, Shinto, Sikh, Tao, Zoroastrian, American Ethical Union, and National Spiritualist Association congregations; and counts of congregations and affiliated individuals for Baháʼí, three Buddhist groupings, two Hindu groupings, four Jewish groupings, and Muslims. Participating groups reported 356,642 congregations with 161,224,088 adherents, comprising 48.6 percent of the total U.S. population of 331,449,281. As explained below, membership totals were estimated for some religious groups.
What are adherents?
To achieve comparability of data, the ASARB staff asks participating bodies to provide or estimates for them their number of adherents. Adherents include full members, non-member children, and other regular participants who are not considered members. For further discussion of how adherents are defined and calculated, see the U.S. Religion Census website. The 2020 U.S. Religion Census included data on congregations and adherents for 217 religious bodies and on congregations only for 155.
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). Steensland et al. justify the major categories we use and classify most of the groups that participated in the 2000 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 here to view religious traditions and the groups that are included in each.
How were Catholics counted?
For the 2020 study, each diocese (both Latin and Eastern) was asked to provide, by parish or mission, their number of registered households, registered individuals, and, for the most recent year available, their number of infant baptisms and deaths. From this information, as well as from several other data sources, a committee of researchers familiar with Catholic demographic issues estimated the likely total number of Catholics within a diocese. Members of this committee were Mary Gautier and Michal Kramarek, both of the Center for Applied Research in the Apostolate at Georgetown University; Michael Cieslak, Director of Research and Planning, Diocese of Rockford, retired; and Lucy Putnam and Clifford Grammich, both of the Glenmary Research Center. infant baptisms within the past year, deaths within the past year, and weekly attendance. Among the other data sources used for this estimation process was a special county-level file of Pew Religious Landscape Survey data made available for this purpose. In assessing survey data for a given diocese, the committee focused on the proportion of the population that claimed to be both (1) Catholic and (2) to attend religious services more frequently than “never.” This, committee members believed, would be equivalent to the number of individuals known to a Catholic congregation in some way.
The amount of data each diocese provided varied. Some dioceses provided complete parish-level data on households, individuals, infant baptisms, and deaths, with the total number of individual Catholics reported according with other sources indicated. For these, the committee agreed that the total number of Catholics reported was what the dioceses reported. Other dioceses might report only the number of household registrations. For these, the committee considered multiple data sources, determined the most likely number of total Catholics, and generally distributed in proportion to the number of households reported (with some adjustments where this would lead to an implausibly higher number of Catholics in a given county). Following our estimation of data by county for each diocese, we gave each diocese an opportunity to comment on our procedures and to suggest revisions.
Altogether, this work identified nearly 62 million Catholic individuals who are likely to be known in some way to a Catholic church in the United States. We believe this to be a conservative estimate of the Catholic population in the United States—indeed, it is below what other national sources indicate—but we recognize that a conservative approach is necessary to ensure that these numbers are relatively consistent across counties. Our conservative approach may have particularly affected estimates in counties where the Catholic population has grown from recent migration, foreign or domestic. Persons wishing additional detail on these figures should write to the Glenmary Research Center at
How were black Protestant churches counted?
Historically, religious bodies focused on the African American population have been less focused on gathering statistics than those groups largely comprising European Americans. This has made it difficult for such groups to take part in religion censuses relying on congregational data.
For the 2020 U.S. Religion Census, we identified 25 historically African American denominations and sought congregation locations and statistics directly from them.
One such group, the United Holy Church of America, Inc., provided a data and statistics.
For the others, we used a variety of online directories and other address lists to estimate congregations and adherents.
Eight groups had online directories and address lists for congregational locations and sizes. These groups should have accurate congregational counts and reasonably accurate adherent figures in the 2020 U.S. Religion Census. They are the African Methodist Episcopal Church; the Christian Methodist Episcopal Church; the Church of Our Lord Jesus Christ of Apostolic Faith; the Cumberland Presbyterian Church in America; the Full Gospel Baptist Church Fellowship; the National Primitive Baptist Convention, USA, Inc.; the Reformed Zion Union Apostolic Church; and the United House of Prayer.
Six groups had online directories, but no congregational information in address lists. These groups should have accurate congregational counts. They are the Church of the Living God (Christian Workers for Fellowship); the Church of the Living God: Pillar and Ground of the Truth, Which He Purchased with His Own Blood, Inc.; the House of God, Which is the Church of the Living God, the Pillar and Ground of the Truth, Inc.; the North Carolina Congregational Conference; the Union American Methodist Episcopal Church; and the United American Free Will Baptist Denomination, Inc.
Seven groups had no online listings but had address list locations and congregational sizes. These groups are known to be underrepresented in the 2020 U.S. Religion Census. They are the African Methodist Episcopal Zion Church; the Church of God in Christ; the National Baptist Convention, USA, Inc.; the National Baptist Convention of America; the National Missionary Baptist Convention, Inc.; the Pentecostal Assemblies of the World; and the Progressive National Baptist Convention.
Three groups had neither online listings nor address list information. As such, we could not include them in the 2020 U.S. Religion Census. They are the Pentecostal Church of Christ; the Reformed Methodist Union Episcopal Church; and the United Pentecostal Church of the Assemblies of God.
For further information on use of mailing lists and other supplemental data, see the U.S. Religion Census website.
How were Jewish estimates computed?
U.S. Religion Census information on Jewish groups was supplied primarily by the Synagogue Studies Institute. The Synagogue Studies Institute provided, by county and adherent tradition, numbers of synagogues and adherents.
The Synagogue Studies Institute derived its counts from lists provided by the four major Jewish movements. These included member congregations and membership totals (or estimates, reported by family units). These four are the Union of Reform Judaism (URJ), United Synagogue of Conservative Judaism (USCJ), Orthodox Union (OU), and Reconstructing Judaism (RJ). OU reported both member and non-member Orthodox synagogues.
In addition, since the 2010 U.S. Religion Census, the number of independent synagogues and those who have disaffiliated with a movement has increased dramatically. In response to this trend, the Synagogue Studies Institute included Independent as a separate designation for 2020. This category includes those synagogues who identify as independent, those who identify as unaffiliated, and those who are part of both Jewish Renewal (https://aleph.org/) and the Society for Secular Humanistic Judaism (SHJ, https://shj.org/). This list was collected manually by phone, email, and website searches.
A few congregations have affiliations with more than one movement. In those cases, each movement was given 0.5 of that congregation in the “Synagogue” column, and 50 percent of the membership units.
The 2020 U.S. Religion Census also includes Chabad as a separate Jewish body. The Synagogue Studies Institute gathered Chabad data from the Chabad website, https://www.chabad.org/. In 2010, many Chabad communities were included with Orthodox synagogues. Yet Chabad is not considered part of Orthodox Judaism or any other movement. Also, not all Chabad locations function as congregations by the common, American definition, i.e., a worshipping community. However, there are over 950 American Chabad locations and not including them in the American synagogue landscape is problematic.
We stress that the reported data are on synagogues and the number of individuals affiliated with them. It is not an estimate of the total Jewish population in the United States and should not be considered as such.
How were the Muslim estimates computed?
The first phase of the Mosque Survey was a count, conducted from June to November 2019, of all U.S. mosques. This count started with the 2010 mosque database, then conducted an internet search to verify the existence of mosques previously counted as well as to identify new ones. This process ultimately identified 2,771 mosques.
The second phase of the Mosque Survey was a comprehensive telephone interview survey of a mosque leader, for which a random sampling of 700 mosques was drawn, of which 470 completed questionnaires, fulfilling the target for each state. The work of completing the questionnaires started in November 2019 and ended in October 2020. The COVID-19 pandemic made the task of finding a mosque leader more difficult and delayed completion of the survey.
For the Mosque Survey, mosques were defined as a Muslim organization that organizes Jum’ah prayer, conducts other Islamic activities, and controls the space in which activities are held. This definition would include “musallas,” which have an organization that does more than just conduct Jum’ah prayers. This definition excludes those places, such as a hospital or airport, where only Jum’ah prayer is held with no other Islamic activities. Some Shi’ite religious organizations do not hold Jum’ah prayer due the absence of a resident scholar or because they consider themselves an Imambargah or Hussainiya; such Shi’ite organizations were classified as mosques. The Mosque Survey did not include Muslim organizations, such as the Nation of Islam, Moorish Science Temple, Ismailis, and Ahmadiyyah, outside the American Muslim community mainstream.
How were Buddhist and Hindu groups counted?
The Buddhist and Hindu groups built on counts that J. Gordon Melton conducted for the Religion Census in 2010. Melton and colleagues called all Buddhist and Hindu congregations that they identified in 2010 and sought to identify additional ones as well. Difficulties associated with the COVID-19 pandemic hindered this effort in some ways and likely prevented a complete count of these traditions. Ultimately, this effort was able to identify 1,984 Buddhist congregations of the same three traditions enumerated in 2010. It also identified 1,811 Hindu congregations which it classified into Hindu traditional temples and Hindu yoga and meditation groups. For a complete discussion of the methods used for these groups and their context within the United States, see the U.S. Religion Census website.
How were non-denominational churches counted?
Over the past two decades, Scott Thumma of the Hartford Institute for Religion Research has collected nondenominational and independent church lists found on the Internet. To this list were added ten more listings of nondenominational congregations, house churches, megachurches, and networks of independent churches that were collected privately and from the web during 2019 and 2020. Three purchased mailing lists of independent and nondenominational Christian congregations were also added to the database. A large percentage of these purchased records included approximate size, email, and website information. After collection, these lists were merged, and the database was then screened for duplicates, incorrect entries, and non-church listings.
Following this effort, a team of eight part-time staff persons spent more than 3,200 hours culling the web to verify the status of these congregations. Every church in the database was checked on Google and online Yellow Pages to confirm its existence as an independent/nondenominational church. Every church was also emailed or called to confirm its independent/nondenominational status, membership, and attendance figures. One of the staff members spoke Spanish and tried to contact Hispanic/Latino churches in the listing. Approximately 30 percent of all congregations contacted in these ways responded to these requests and verified their information. While engaged in this research, the staff found additional church lists from local websites (e.g., of newspapers, municipalities, and counties) that added new independent and nondenominational churches. Staff further gathered church suggestions from Google and Facebook on previously unknown nondenominational churches. The team then attempted to confirm the information on these suggested churches using the above method.
The result was a database that contained over 69,127 potential entries. Nearly 30,000 were removed due to uncertainty about their existence, size, nondenominational status, or being a part of the Vineyard Christian Fellowship or Calvary Chapel Networks (which are listed separately in the U.S. Religion Census). The resulting 44,319 congregations with 21,098,641 adherents in 2,753 counties are the best estimate of the independent and nondenominational churches in the United States.
Even given these efforts, the current listing is not entirely accurate. The independent status or exact size of many churches could not be confirmed. Additionally, doing random checks in several cities nearly a year later, the team found many of the previously confirmed congregations had already closed and a few new ones were discovered. Several nondenominational churches listed are likely to be affiliated with a denomination but did not indicate it on their website, in their published material, or in project contact with them.
Nondenominational and independent congregations are a very fluid grouping of churches. This label also can be, in the minds of many clergy, a nonexclusive category, and more of a marketing brand label than an explicit organizational or affiliation identifier. Therefore, while this is the best accounting of nondenominational churches, it is not to be assumed as comprehensive or totally accurate.
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, congregational adherents overcount, and individuals’ county of residence differing from county of congregational adherence.
