India is the most populous country in the world with one-sixth of the world's population. According to estimates from the United Nations (UN), India has overtaken China as the country with the largest population in the world, with a population of 1,425,775,850 at the end of April 2023.
The population of the United Kingdom was estimated at 67,596,281 in 2022. It is the 21st most populated country in the world and has a population density of 279 people per square kilometre, with England having significantly greater density than Wales, Scotland, and Northern Ireland. Almost a third of the population lives in south east England, which is predominantly urban and suburban, with 8,866,180 people in the capital city, London, whose population density was 5,640 inhabitants per square kilometre (14,600/sq mi) in 2022.
According to data from the 1989 Soviet census, the population of the USSR was made up of 70% East Slavs and 17% Turkic peoples, with no other single ethnic group making up more than 2%. Alongside the atheist majority of 60%, there were sizable minorities of Russian Orthodox Christians and Muslims.
The United States is a country primarily located in North America. Demographics of the United States concern matters of population density, ethnicity, education level, health of the populace, economic status, religious affiliations, and other aspects regarding the population.
In demography, demographic transition is a phenomenon and theory which refers to the historical shift from high birth rates and high death rates to low birth rates and low death rates, as societies attain more technology, education and economic development. The demographic transition has occurred in most of the world over the past two centuries, bringing the unprecedented population growth of the post-Malthusian period, then reducing birth rates and population growth significantly in all regions of the world. The demographic transition strengthens economic growth process by three changes: (i) reduced dilution of capital and land stock, (ii) increased investment in human capital, and (iii) increased size of the labor force relative to the total population and changed age population distribution. Although this shift has occurred in many industrialized countries, the theory and model are frequently imprecise when applied to individual countries due to specific social, political and economic factors affecting particular populations.
Zero population growth, sometimes abbreviated ZPG, is a condition of demographic balance where the number of people in a specified population neither grows nor declines; that is, the number of births plus in-migrants equals the number of deaths plus out-migrants. ZPG has been a prominent political movement since the 1960s.
The total fertility rate (TFR) of a population is the average number of children that are born to a woman over her lifetime, if they were to experience the exact current age-specific fertility rates (ASFRs) through their lifetime, and they were to live from birth until the end of their reproductive life.
Population decline, also known as depopulation, is a reduction in a human population size. Throughout history, Earth's total human population has continued to grow; however, current projections suggest that this long-term trend of steady population growth may be coming to an end.
Population growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800 to 8.1 billion in 2024. The UN projected population to keep growing, and estimates have put the total population at 8.6 billion by mid-2030, 9.8 billion by mid-2050 and 11.2 billion by 2100. However, some academics outside the UN have increasingly developed human population models that account for additional downward pressures on population growth; in such a scenario population would peak before 2100. Others have challenged many recent population projections as having underestimated population growth.
The Mongol invasions and conquests took place during the 13th and 14th centuries, creating history's largest contiguous empire, the Mongol Empire (1206–1368), which by 1260 covered large parts of Eurasia. Historians regard the Mongol devastation as one of the deadliest episodes in history.
Demographic dividend, as defined by the United Nations Population Fund (UNFPA), is "the economic growth potential that can result from shifts in a population’s age structure, mainly when the share of the working-age population is larger than the non-working-age share of the population ". In other words, it is "a boost in economic productivity that occurs when there are growing numbers of people in the workforce relative to the number of dependents". UNFPA stated that "a country with both increasing numbers of young people and declining fertility has the potential to reap a demographic dividend."
Ansley Johnson Coale, was one of America's foremost demographers. A native to Baltimore, Maryland, he earned his Bachelor of Arts in 1939, his Master of Arts in 1941, and his Ph.D. in 1947, all at Princeton University. A long-term director of the Office of Population Research at Princeton, Coale was especially influential for his work on the demographic transition and for his leadership of the European Fertility Project.
This article lists current estimates of the world population in history. In summary, estimates for the progression of world population since the Late Middle Ages are in the following ranges:
The middle of the 20th century was marked by a significant and persistent increase in fertility rates in many countries of the world, especially in the Western world. The term baby boom is often used to refer to this particular boom, generally considered to have started immediately after World War II, although some demographers place it earlier or during the war. This terminology led to those born during this baby boom being nicknamed the baby boomer generation.
The Mongol conquests resulted in widespread and well-documented death and destruction throughout Eurasia, as the Mongol army invaded hundreds of cities and killed millions of people. One estimate is that approximately 10% of the contemporary global population, amounting to some 37.75–60 million people, was killed either during or immediately after the Mongols' military campaigns. As such, the Mongol Empire, which remains the largest contiguous polity to ever have existed, is regarded as having perpetrated some of the deadliest acts of mass killing in human history.
In world demographics, the world population is the total number of humans currently alive. It was estimated by the United Nations to have exceeded eight billion in mid-November 2022. It took around 300,000 years of human prehistory and history for the human population to reach a billion and only 218 years more to reach 8 billion.
The Roman Empire's population has been estimated at between 59 and 76 million in the 1st and 2nd centuries, peaking probably just before the Antonine Plague. Historian Kyle Harper provides an estimate of a population of 75 million and an average population density of about 20 people per square kilometre at its peak, with unusually high urbanization. During the 1st and 2nd centuries CE, the population of the city of Rome is conventionally estimated at one million inhabitants. Historian Ian Morris estimates that no other city in Western Eurasia would have as many again until the 19th century.
Earth has a human population of over 8 billion as of 2024, with an overall population density of 50 people per km2. Nearly 60% of the world's population lives in Asia, with more than 2.8 billion in the countries of India and China combined. The percentage shares of China, India and rest of South Asia of the world population have remained at similar levels for the last few thousand years of recorded history. The world's literacy rate has increased dramatically in the last 40 years, from 66.7% in 1979 to 86.3% today. Lower literacy levels are mostly attributable to poverty. Lower literacy rates are found mostly in South Asia and Sub-Saharan Africa.
Projections of population growth are attempts to show how the human population statistics might change in the future. These projections are an important input to forecasts of the population's impact on this planet and humanity's future well-being. Models of population growth take trends in human development and apply projections into the future. These models use trend-based-assumptions about how populations will respond to economic, social and technological forces to understand how they will affect fertility and mortality, and thus population growth.
The population history of China covers the long-term pattern of population growth in China and its impact on the history of China. The population went through many cycles that generally reached peaks along each imperial power and was decimated due to wars and barbarian invasions. The census data shows that the population as percentage share of the world has a long-term average of 26%, with 6% standard deviation. The minimum could be as low as 16% while the maximum as high as 33%. In the late 19th century and the early 20th century, the percentage share has been trending down. This was caused by two opposite factors: On one hand, the world population has been growing explosively. On the other hand, in order to address the poverty issue, China implemented a strict birth control policy. For recent trends see demographics of China and China.
