In 2022, around 31.6 percent of the global population were identify as Christian. Around 25.8 percent of the global population identify as Muslims, followed by 15.1 percent of global populations as Hindu.

As of 2010, Christianity was the religion with the most followers worldwide, followed by Islam (Muslims) and Hinduism. In the forty years between 2010 and 2050, it is projected that the landscape of world religions will undergo some noticeable changes, with the number of Muslims almost catching up to Christians. The changes in population sizes of each religious group is largely dependent on demographic development, for example, the rise in the world's Christian population will largely be driven by population growth in Sub-Saharan Africa, while Muslim populations will rise across various regions of Africa and South Asia. As India's population is set to grow while China's goes into decline, this will be reflected in the fact that Hindus will outnumber the unaffiliated by 2050. In fact, India may be home to both the largest Hindu and Muslim populations in the world by the middle of this century.

From 2022 to 2060, the worldwide population of Muslims is expected to increase by 45.7 percent. For the same period, the global population of Buddhists is expected to decrease by 12.2 percent.

In 2023, 27.5 percent of Americans were unaffiliated with any religion. A further 13.4 percent of Americans were White evangelical Protestants, and an additional 13.3 percent were White mainline Protestants. Religious trends in the United States Although the United States is still home to the largest number of Christians worldwide, the nation has started to reflect a more diverse religious landscape in recent years. Americans now report a wide range of religious beliefs and backgrounds, in addition to an increasing number of people who are choosing to identify with no religion at all. Studies suggest that many Americans have left their previous religion to instead identify as atheist, agnostic, or nothing in particular, with many reasoning that they stopped believing in the religion's teachings, that they didn't approve of negative teachings or treatment of LGBTQ+ people, or that their family was never that religious growing up. Christian controversies Over the last few years, controversies linked to Christian denominations have plagued the nation, including reports of child sexual abuse by the Catholic Church, the Church of Jesus Christ of Latter-day Saints, and the Southern Baptist Convention. Christian churches have also been accused of supporting discriminatory actions against LGBTQ+ people and people belonging to other religious groups. In addition, there have been increasing concerns about Christian nationalism, the political ideology that asserts that America was founded to be a Christian nation. Although the majority of Americans still think that declaring the United States a Christian nation would go against the U.S. Constitution, studies found that most Republicans would be in favor of this change.

Sikhism is a religion that originated on the Indian subcontinent during the fifteenth century. Sikhs follow the teachings of 'gurus', who descend from the first guru Guru Naruk who established the faith. Followers of Sikhism are monotheists, believing in only one god, and other core beliefs include the need to meditate, the importance of community and communal living, and the need to serve humanity selflessly (or 'seva'). Sikhism and the British Empire In total, there are around 26 million Sikhs worldwide, and over 24 million of these live in India. Outside of India, the largest Sikh populations are mostly found in former territories of the British Empire - the UK and Canada both have Sikh populations of over half a million people. Migration from India to other parts of the British Empire was high in the 19th century, due to the labor demands of relatively newer colonies, as well as those where slavery had been abolished. These countries also remain popular destinations for Sikh migrants today, as many are highly trained and English-speaking. Other regions with significant Sikh populations Italy also has a sizeable Sikh population, as many migrated there after serving there in the British Army during WWI, and they are now heavily represented in Italy's dairy industry. The Sikh population of Saudi Arabia is also reflective of the fact that the largest Indian diaspora in the world can now be found in the Middle East - this is due to the labor demands of the fossil fuel industries and their associated secondary industries, although a large share of Indians in this part of the world are there on a temporary basis.

World Population World Population and top 20 Countries Live Clock. Population in the past, present, and future. Milestones. Global Growth Rate. World population by Region and by Religion. Population Density, Fertility Rate, Median Age, Migrants. All-time population total.

Associated with manuscript titled: Fifty Muslim-majority countries have fewer COVID-19 cases and deaths than the 50 richest non-Muslim countriesThe objective of this research was to determine the difference in the total number of COVID-19 cases and deaths between Muslim-majority and non-Muslim countries, and investigate reasons for the disparities. Methods: The 50 Muslim-majority countries had more than 50.0% Muslims with an average of 87.5%. The non-Muslim country sample consisted of 50 countries with the highest GDP while omitting any Muslim-majority countries listed. The non-Muslim countries’ average percentage of Muslims was 4.7%. Data pulled on September 18, 2020 included the percentage of Muslim population per country by World Population Review15 and GDP per country, population count, and total number of COVID-19 cases and deaths by Worldometers.16 The data set was transferred via an Excel spreadsheet on September 23, 2020 and analyzed. To measure COVID-19’s incidence in the countries, three different Average Treatment Methods (ATE) were used to validate the results. Results published as a preprint at https://doi.org/10.31235/osf.io/84zq5(15) Muslim Majority Countries 2020 [Internet]. Walnut (CA): World Population Review. 2020- [Cited 2020 Sept 28]. Available from: http://worldpopulationreview.com/country-rankings/muslim-majority-countries (16) Worldometers.info. Worldometer. Dover (DE): Worldometer; 2020 [cited 2020 Sept 28]. Available from: http://worldometers.info

Based on the 2020 census, the majority of Filipino households were affiliated with the Roman Catholic religion, numbering about 86 million people. Meanwhile, there were roughly seven million Muslims in the country. The Philippines is one of the countries in the world with the highest population professing the Catholic faith, after Brazil and Mexico.

Christianity is the major religion in numerous African countries. As of 2024, around 96 percent of the population of Zambia was Christian, representing the highest percentage on the continent. Seychelles and Rwanda followed with roughly 95 percent and 94 percent of the population being Christian, respectively. While these countries present the highest percentages, Christianity was also prevalent in many other African nations. For instance, in South Africa, Christianity was the religion of nearly 85 percent of the people, while the share corresponded to 71 percent in Ghana. Religious variations across Africa Christianity and Islam are the most practiced religions in Africa. Christian adherents are prevalent below the Sahara, while North Africa is predominantly Muslim. In 2020, Christians accounted for around 60 percent of the Sub-Saharan African population, followed by Muslims with a share of roughly 30 percent. In absolute terms, there were approximately 650 million Christians in the region, a number forecast to increase to over one billion by 2050. In contrast, Islam is most prevalent in North Africa, being the religion of over 90 percent of the population in Algeria, Morocco, Tunisia, and Libya. Christianity in the world As opposed to other religions, Christianity is widely spread across continents worldwide. In fact, Sub-Saharan Africa, Latin America and the Caribbean, and Europe each account for around 25 percent of the global Christian population. By comparison, Asia-Pacific and North America make up 13 percent and 12 percent of Christians worldwide, respectively. In several regions, Christians also suffer persecution on religious grounds. Somalia and Libya presented the most critical situation in Africa in 2021, reporting the strongest suppression of Christians worldwide just after North Korea and Afghanistan.

In 2022, Indonesia has the largest population of Muslims worldwide with around 241.5 million. This was followed with around 225.6 million Muslims in Pakistan and 211.16 million Muslims in India.

Philippines Population: RA: Iglesia ni Cristo data was reported at 2,664,498.000 Person in 2015. This records an increase from the previous number of 2,469,957.000 Person for 2010. Philippines Population: RA: Iglesia ni Cristo data is updated yearly, averaging 2,469,957.000 Person from Dec 2000 (Median) to 2015, with 3 observations. The data reached an all-time high of 2,664,498.000 Person in 2015 and a record low of 1,762,845.000 Person in 2000. Philippines Population: RA: Iglesia ni Cristo data remains active status in CEIC and is reported by Philippine Statistics Authority. The data is categorized under Global Database’s Philippines – Table PH.G003: Population: Religious: Affiliation.

According to a survey conducted in South Korea in 2023, over 60 percent of respondents reported no religious affiliation, while approximately 20 percent identified as Christians and 16 percent as Buddhists. Religious population South Korea is a multi-religious society where Christianity, Buddhism, and various other religions coexist with shamanism. According to a previous study, the domestic religious population appeared to decline over time after reaching its peak in 2005, at nearly 25 million people. In contrast, the share of people who are religiously unaffiliated has increased in recent years. Within the last two decades, the religiously unaffiliated population has increased from about 40 percent to more than 60 percent. Shamanism Shamanism has continued to significantly influence the daily lives of many South Koreans. According to a survey conducted in 2023, about 40 percent of respondents reported having consulted a fortune-teller within the past year. Roughly 80 percent of those respondents were already affiliated with a religion.

Sri Lanka LK: Sex Ratio at Birth: Male Births per Female Births data was reported at 1.043 Ratio in 2017. This records an increase from the previous number of 1.042 Ratio for 2016. Sri Lanka LK: Sex Ratio at Birth: Male Births per Female Births data is updated yearly, averaging 1.042 Ratio from Dec 1962 (Median) to 2017, with 21 observations. The data reached an all-time high of 1.046 Ratio in 1987 and a record low of 1.035 Ratio in 1967. Sri Lanka LK: Sex Ratio at Birth: Male Births per Female Births data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s Sri Lanka – Table LK.World Bank.WDI: Population and Urbanization Statistics. Sex ratio at birth refers to male births per female births. The data are 5 year averages.; ; United Nations Population Division. World Population Prospects: 2017 Revision.; Weighted average;

As of 2020, 32.2 percent of Iranian survey respondents stated that they follows the Shia Muslim belief. This was followed by 22.2 percent of respondents who said that they have no religious belief.

In 2020, around 98.5 percent of the Iranian population identified as Muslim. Around 81 percent identified as Shia Muslims in the same year, while a much smaller share followed the Sunni Muslim religion. In Iran, most Sunni Muslims belong to ethnic minority groups.

Iran’s demographics
The total population in Iran has grown steadily and is expected to surpass 90 million in 2028. The vast majority of the population in the country was between 15 and 64 years of age. At the same time, the share of people aged above 64 increased in recent years and constituted over seven percent of the total population.

Muslim population worldwide

In Europe, it was estimated that the Muslim population could triple by the middle of the century. In Southeast Asia, Indonesia had the largest share of Muslims as a proportion of its population. On the African continent, the highest number of Muslims was estimated in Nigeria, with close to a hundred million Islam followers. In the United States, less than one percent of the population identified as Muslims.

In 2023, over 87 percent of Indonesians declared themselves to be Muslim, followed by 7.4 percent who were Christians. Indonesia has the largest Islamic population in the world and for this reason is often recognized as a Muslim nation. However, Indonesia is not a Muslim nation according to its constitution. The archipelago is a multifaith country and officially recognizes six religions – Islam, Protestantism, Catholicism, Buddhism, Hinduism, and Confucianism.

Not all provinces in Indonesia are Muslim majority
The spread of Islam in Indonesia began on the west side of the archipelago, where the main maritime trade routes were located. Until today, most of the Indonesian Muslim population are residing in Western and Central Indonesia, while the majority religion of several provinces in Eastern Indonesia, such as East Nusa Tenggara and Bali, is Christian and Hindu, respectively.

Discrimination towards other beliefs in Indonesia The Indonesian constitution provides for freedom of religion. However, the Government Restrictions Index Score on religion in Indonesia is relatively high. Indonesians who practice unrecognized religions, including Indonesia’s indigenous or traditional belief systems, such as animism, dynamism, and totemism, face legal restrictions and discrimination. Indonesian law requires its citizens to put one of the recognized religions on their national identity cards, with some exceptions for indigenous religions. Although legally citizens may leave the section blank, atheism or agnosticism is considered uncommon in Indonesia.

Islam is the major religion in many African countries, especially in the north of the continent. In Comoros, Libya, Western Sahara, at least 99 percent of the population was Muslim as of 202. These were the highest percentages on the continent. However, also in many other African nations, the majority of the population was Muslim. In Egypt, for instance, Islam was the religion of 79 percent of the people. Islam and other religions in Africa Africa accounts for an important share of the world’s Muslim population. As of 2019, 16 percent of the Muslims worldwide lived in Sub-Saharan Africa, while 20 percent of them lived in the Middle East and North Africa (MENA) region. Together with Christianity, Islam is the most common religious affiliation in Africa, followed by several traditional African religions. Although to a smaller extent, numerous other religions are practiced on the continent: these include Judaism, the Baha’i Faith, Hinduism, and Buddhism. Number of Muslims worldwide Islam is one of the most widespread religions in the world. There are approximately 1.9 billion Muslims globally, with the largest Muslim communities living in the Asia-Pacific region. Specifically, Indonesia hosts the highest number of Muslims worldwide, amounting to over 200 million, followed by India, Pakistan, and Bangladesh. Islam is also present in Europe and America. The largest Islamic communities in Europe are in France (5.72 million), Germany (4.95 million), and the United Kingdom (4.13 million). In the United States, there is an estimated number of around 3.45 million Muslims.

Based on the 2020 census, Region 5 or the Bicol Region registered the highest share of households who reported Roman Catholic as their religious affiliation at 93.5 percent. This was followed by Region 8 or Eastern Visayas with a share of 92.3 percent. In contrast, only five percent of households in BARMM were Roman Catholics. The Philippines is one of the countries in the world with the highest population professing the Catholic faith, after Brazil and Mexico.

In 1800, the population of the modern-day territory of Iran was approximately 6.3 million. This figure would see modest growth throughout the 19th century, as several wars and a mass famine in 1870-1871 (modern estimates put its death toll at around 1.5 million people) were largely balanced out by a surge in migration to Iran; this migration came as the Russian Empire expanded into the Caucuses, and caused a wave of refugees to flee southwards to avoid forced expulsion and ethnic cleansing in the North Caucasus region, particularly from 1864 onwards. As a result, the population of Iran reached ten million by the turn of the 20th century.

Twentieth century growth Iran’s population would begin to grow rapidly in the 20th century, as the discovery of oil in the country in 1908 led to an economic boom, and the socio-economic reforms implemented under Reza Shah would see a number of medical and healthcare advancements across the country. Although unpopular with religious fundamentalists, Reza Shah's reforms had long-term influence on the demographic development of Iran, even after his abdication in 1941. Following the Second World War, Iran became increasingly westernized and developed relatively strong relations with the U.S.; however, western influence, economic imbalances and the oppression of the Mohammed Reza Shah's regime became the driving forces behind the Iranian Revolution, which was one of the most significant moments in the history of the region.

Growth after the Revolution The 1979 Iranian Revolution saw the removal of the Shah and an end to Iran's so called westernization; the monarchy was replaced by an Islamic, theocratic regime led by the Supreme Leader, Ayatollah Ruhollah Khomeini. During Khomeini's decade in charge he oversaw Iran's transition into an Islamic Republic, which implemented radical political and cultural changes in the country, and this coincided with an increased population growth rate in the 1980s. This growth was promoted by the Iranian government, who encouraged a baby boom during the Iran–Iraq War between 1980 and 1988, as part of an effort to increase future Iranian military manpower. As a result of this strategy, the population of Iran would grow from approximately 38.6 million in 1980 to over 56 million just a decade later. Following the implementation of a UN-brokered ceasefire in 1988, population growth in Iran would slow, as economic sanctions and government implementation of family planning policies would lead to a drop in fertility. Population growth has continued steadily into the 21st century, however, and in 2020, Iran is estimated to have a population of 84 million.

In 1800, the population of the area of modern-day Bangladesh was estimated to be just over 19 million, a figure which would rise steadily throughout the 19th century, reaching over 26 million by 1900. At the time, Bangladesh was the eastern part of the Bengal region in the British Raj, and had the most-concentrated Muslim population in the subcontinent's east. At the turn of the 20th century, the British colonial administration believed that east Bengal was economically lagging behind the west, and Bengal was partitioned in 1905 as a means of improving the region's development. East Bengal then became the only Muslim-majority state in the eastern Raj, which led to socioeconomic tensions between the Hindu upper classes and the general population. Bengal Famine During the Second World War, over 2.5 million men from across the British Raj enlisted in the British Army and their involvement was fundamental to the war effort. The war, however, had devastating consequences for the Bengal region, as the famine of 1943-1944 resulted in the deaths of up to three million people (with over two thirds thought to have been in the east) due to starvation and malnutrition-related disease. As the population boomed in the 1930s, East Bengal's mismanaged and underdeveloped agricultural sector could not sustain this growth; by 1942, food shortages spread across the region, millions began migrating in search of food and work, and colonial mismanagement exacerbated this further. On the brink of famine in early-1943, authorities in India called for aid and permission to redirect their own resources from the war effort to combat the famine, however these were mostly rejected by authorities in London. While the exact extent of each of these factors on causing the famine remains a topic of debate, the general consensus is that the British War Cabinet's refusal to send food or aid was the most decisive. Food shortages did not dissipate until late 1943, however famine deaths persisted for another year. Partition to independence Following the war, the movement for Indian independence reached its final stages as the process of British decolonization began. Unrest between the Raj's Muslim and Hindu populations led to the creation of two separate states in1947; the Muslim-majority regions became East Pakistan (now Bangladesh) and West Pakistan (now Pakistan), separated by the Hindu-majority India. Although East Pakistan's population was larger, power lay with the military in the west, and authorities grew increasingly suppressive and neglectful of the eastern province in the following years. This reached a tipping point when authorities failed to respond adequately to the Bhola cyclone in 1970, which claimed over half a million lives in the Bengal region, and again when they failed to respect the results of the 1970 election, in which the Bengal party Awami League won the majority of seats. Bangladeshi independence was claimed the following March, leading to a brutal war between East and West Pakistan that claimed between 1.5 and three million deaths in just nine months. The war also saw over half of the country displaced, widespread atrocities, and the systematic rape of hundreds of thousands of women. As the war spilled over into India, their forces joined on the side of Bangladesh, and Pakistan was defeated two weeks later. An additional famine in 1974 claimed the lives of several hundred thousand people, meaning that the early 1970s was one of the most devastating periods in the country's history. Independent Bangladesh In the first decades of independence, Bangladesh's political hierarchy was particularly unstable and two of its presidents were assassinated in military coups. Since transitioning to parliamentary democracy in the 1990s, things have become comparatively stable, although political turmoil, violence, and corruption are persistent challenges. As Bangladesh continues to modernize and industrialize, living standards have increased and individual wealth has risen. Service industries have emerged to facilitate the demands of Bangladesh's developing economy, while manufacturing industries, particularly textiles, remain strong. Declining fertility rates have seen natural population growth fall in recent years, although the influx of Myanmar's Rohingya population due to the displacement crisis has seen upwards of one million refugees arrive in the country since 2017. In 2020, it is estimated that Bangladesh has a population of approximately 165 million people.