World population
In world demographics, the world population is the total number of humans currently alive. It was estimated by the United Nations to have exceeded 8 billion on November 15, 2022. It took around 300,000 years of human prehistory and history for the human population to reach a billion and only 218 more years from there to reach 8 billion. As of 2026, the world population is approximately 8.3 billion.
The human population experienced continuous growth following the Great Famine of 1315–1317 and the end of the Black Death in 1350, when it had reached nearly 370 million. The highest global population growth rates, with increases of over 1.8% per year, occurred between 1955 and 1975, peaking at 2.1% between 1965 and 1970. The growth rate declined to 1.1% between 2015 and 2020 and is projected to decline further in the 21st century. The global population is still increasing, but there is significant uncertainty about its long-term trajectory due to changing fertility and mortality rates. The UN Department of Economics and Social Affairs has projected the world population to reach between 9 and 10 billion people by 2050, providing an 80% confidence interval of 10–12 billion by the end of the 21st century, with a growth rate by then of zero. However, other demographers predict that the human population may begin to decline in the second half of the 21st century if global fertility rates continue to fall.
The total number of births globally, as of 2024, is approximately 132 million/year, which is projected to peak during the period 2040–2045 at 141 million/year and then decline slowly to 126 million/year by 2100. The total number of deaths is currently 63 million/year and is projected to grow steadily to 122 million/year by 2100.
The global median age of human beings, as of 2026, is 31.1 years.
History
Estimates of world population by their nature are an aspect of modernity, possible only since the Age of Discovery. Early estimates for the population of the world date to the 17th century: William Petty, in 1682, estimated the world population at 320 million ; by the late 18th century, estimates ranged close to one billion. More refined estimates, broken down by continents, were published in the first half of the 19th century, at 600 million to 1 billion in the early 1800s and 800 million to 1 billion in the 1840s.It is difficult for estimates to be better than rough approximations, as even current population estimates are fraught with uncertainties from 3% to 5%.
Prehistoric patterns
The history of the world's population involves a great deal of speculation. Before 9000 BC, virtually all humans were hunter-gatherers living in small bands that usually verged on the edge of extinction. Survival depended on the capture of hunted animals; if supply of animals dwindled for any reason, humans would starve; if the human population grew too large the number of surviving animals would shrink, leading to starvation the next year for the hunters. The hunting cultures sometimes fished, and usually gathered wild seeds and nuts, but they did not plant or grow vegetables or any other crops. One very rough estimate is 8 million hunters lived circa 9000 BC when the first of several "agricultural revolutions" occurred in the eastern hemisphere. Around the year 9000 BC in the Middle East, for reasons unknown, some groups began to domesticate and graze sheep. The practice of cultivating plants was invented independently in three places: in the Middle East and Europe, in Southeast Asia, and in Central America and Peru.Agriculture provided a steady food supply that could be stored for a year or longer in order to minimize the risk of famine. Farm production could be expanded by systematic human exertion. The new technology of farming meant that the food supply was proportional to the number of workers who could plant and harvest the crops. Every new pair of hands meant more food for the community, so children were valued in agricultural societies. Later, additional workers found useful work in building irrigation canals and systems that provided a stable water supply for crops, especially in Egypt, Mesopotamia, India, China, Peru and Mexico. The population could now grow because new people paid their own way. However, death rates were high, especially for infants and children, so even with high birth rates growth was slow. The same amount of land could support either 1,000 hunters or 100,000 farmers, and it is easy to see which side ultimately would win a fight for the land. Farmers gathered in permanent villages, and through a process of warfare consolidated into much larger states, including those in China, India, Egypt and Mesopotamia. From 300 to 1400 AD large agricultural states also existed throughout the eastern United States, called the "Hopewell tradition" and "Mississippian cultures". They are most famous as Mound Builders, but their culture collapsed by 1500. The natives encountered by the English and French were nomadic hunters who supplemented their meat diet with cultivated vegetables.
Ancient and post-classical history
Estimates of the population of the world at the time agriculture emerged in around 10,000 BC have ranged between 1 million and 15 million. Even earlier, genetic evidence suggests humans may have gone through a population bottleneck of between 1,000 and 10,000 people about 70,000 BC, according to the now largely discredited Toba catastrophe theory. By contrast, it is estimated that around 50–60 million people lived in the combined eastern and western Roman Empire in the 4th century AD.The Plague of Justinian caused Europe's population to drop by around 50% between the 6th and 8th centuries AD. The population of Europe was more than 70 million in 1340. From 1340 to 1400, the world's population fell from an estimated 443 million to 350–375 million, with the Indian subcontinent suffering the most tremendous loss and Europe suffering the Black Death pandemic; it took 200 years for European population figures to recover. The population of China decreased from 123 million in 1200 to 65 million in 1393, presumably from a combination of Mongol invasions, famine, and plague.
Starting in AD 2, the Han dynasty of ancient China kept consistent family registers to properly assess the poll taxes and labor service duties of each household. In that year, the population of Western Han was recorded as 57,671,400 individuals in 12,366,470 households, decreasing to 47,566,772 individuals in 9,348,227 households by AD 146, towards the end of the Han dynasty. From 200 to 400, the world population fell from an estimated 257 million to 206 million, with China suffering the greatest loss. At the founding of the Ming dynasty in 1368, China's population was reported to be close to 60 million; toward the end of the dynasty in 1644, it may have approached 150 million. England's population reached an estimated 5.6 million in 1650, up from an estimated 2.6 million in 1500. New crops that were brought to Asia and Europe from the Americas by Portuguese and Spanish colonists in the 16th century are believed to have contributed to population growth. Since their introduction to Africa by Portuguese traders in the 16th century, maize and cassava have similarly replaced traditional African crops as the most important staple food crops grown on the continent.
The pre-Columbian population of the Americas is uncertain; historian David Henige called it "the most unanswerable question in the world." By the end of the 20th century, scholarly consensus favored an estimate of roughly 55 million people, but numbers from various sources have ranged from 10 million to 100 million. Encounters between European explorers and populations in the rest of the world often introduced local epidemics of extraordinary virulence. According to the most extreme scholarly claims, as many as 90% of the Native American population of the New World died of Old World diseases such as smallpox, measles, and influenza. Over the centuries, the Europeans had developed high degrees of immunity to these diseases, while the indigenous peoples had no such immunity.
Modern history
During the European Agricultural and Industrial Revolutions, the life expectancy of children increased dramatically. The percentage of the children born in London who died before the age of five decreased from 74.5% in 1730–1749 to 31.8% in 1810–1829. Between 1700 and 1900, Europe's population increased from about 100 million to over 400 million. Altogether, the areas populated by people of European descent comprised 36% of the world's population in 1900.Population growth in the Western world became more rapid after the introduction of vaccination and other improvements in medicine and sanitation. Improved material conditions led to the population of Britain increasing from 10 million to 40 million in the 19th century. The population of the United Kingdom reached 60 million in 2006. The United States saw its population grow from around 5.3 million in 1800 to 106 million in 1920, exceeding 307 million in 2010.
20th century
The first half of the 20th century in Imperial Russia and the Soviet Union was marked by a succession of major wars, famines and other disasters which caused large-scale population losses. After the collapse of the Soviet Union, Russia's population declined significantly – from 150 million in 1991 to 143 million in 2012 – but by 2013 this decline appeared to have halted.Many countries in the developing world have experienced extremely rapid population growth since the early 20th century, due to economic development and improvements in public health. China's population rose from approximately 430 million in 1850 to 580 million in 1953, and now stands at over 1.3 billion. The population of the Indian subcontinent, which was about 125 million in 1750, increased to 389 million in 1941; today, India, Pakistan and Bangladesh are collectively home to about billion people. Java, an island in Indonesia, had about 5 million inhabitants in 1815; it had a population of over 139 million in 2020. In just one hundred years, the population of Brazil decupled, from about 17 million in 1900, or about 1% of the world population in that year, to about 176 million in 2000, or almost 3% of the global population in the very early 21st century. Mexico's population grew from 13.6 million in 1900 to about 112 million in 2010. Between the 1920s and 2000s, Kenya's population grew from 2.9 million to 37 million.