In 2023, the population of the United Kingdom reached 68.3 million, compared with 67.6 million in 2022. The UK population has more than doubled since 1871 when just under 31.5 million lived in the UK and has grown by around 8.2 million since the start of the twenty-first century. For most of the twentieth century, the UK population steadily increased, with two noticeable drops in population occurring during World War One (1914-1918) and in World War Two (1939-1945). Demographic trends in postwar Britain After World War Two, Britain and many other countries in the Western world experienced a 'baby boom,' with a postwar peak of 1.02 million live births in 1947. Although the number of births fell between 1948 and 1955, they increased again between the mid-1950s and mid-1960s, with more than one million people born in 1964. Since 1964, however, the UK birth rate has fallen from 18.8 births per 1,000 people to a low of just 10.2 in 2020. As a result, the UK population has gotten significantly older, with the country's median age increasing from 37.9 years in 2001 to 40.7 years in 2022. What are the most populated areas of the UK? The vast majority of people in the UK live in England, which had a population of 57.7 million people in 2023. By comparison, Scotland, Wales, and Northern Ireland had populations of 5.44 million, 3.13 million, and 1.9 million, respectively. Within England, South East England had the largest population, at over 9.38 million, followed by the UK's vast capital city of London, at 8.8 million. London is far larger than any other UK city in terms of urban agglomeration, with just four other cities; Manchester, Birmingham, Leeds, and Glasgow, boasting populations that exceed one million people.

Historical chart and dataset showing total population for the United Kingdom by year from 1950 to 2025.

The total population in the United Kingdom was estimated at 69.2 million people in 2024, according to the latest census figures and projections from Trading Economics. This dataset provides the latest reported value for - United Kingdom Population - plus previous releases, historical high and low, short-term forecast and long-term prediction, economic calendar, survey consensus and news.

The population of England was estimated to have reached almost 57.7 million in 2023, compared with 53.9 million ten years earlier in 2013. Compared with 1971, the population of England has grown by over ten million.

In the past four centuries, the population of the United States has grown from a recorded 350 people around the Jamestown colony of Virginia in 1610, to an estimated 331 million people in 2020. The pre-colonization populations of the indigenous peoples of the Americas have proven difficult for historians to estimate, as their numbers decreased rapidly following the introduction of European diseases (namely smallpox, plague and influenza). Native Americans were also omitted from most censuses conducted before the twentieth century, therefore the actual population of what we now know as the United States would have been much higher than the official census data from before 1800, but it is unclear by how much. Population growth in the colonies throughout the eighteenth century has primarily been attributed to migration from the British Isles and the Transatlantic slave trade; however it is also difficult to assert the ethnic-makeup of the population in these years as accurate migration records were not kept until after the 1820s, at which point the importation of slaves had also been illegalized. Nineteenth century In the year 1800, it is estimated that the population across the present-day United States was around six million people, with the population in the 16 admitted states numbering at 5.3 million. Migration to the United States began to happen on a large scale in the mid-nineteenth century, with the first major waves coming from Ireland, Britain and Germany. In some aspects, this wave of mass migration balanced out the demographic impacts of the American Civil War, which was the deadliest war in U.S. history with approximately 620 thousand fatalities between 1861 and 1865. The civil war also resulted in the emancipation of around four million slaves across the south; many of whose ancestors would take part in the Great Northern Migration in the early 1900s, which saw around six million black Americans migrate away from the south in one of the largest demographic shifts in U.S. history. By the end of the nineteenth century, improvements in transport technology and increasing economic opportunities saw migration to the United States increase further, particularly from southern and Eastern Europe, and in the first decade of the 1900s the number of migrants to the U.S. exceeded one million people in some years. Twentieth and twenty-first century The U.S. population has grown steadily throughout the past 120 years, reaching one hundred million in the 1910s, two hundred million in the 1960s, and three hundred million in 2007. In the past century, the U.S. established itself as a global superpower, with the world's largest economy (by nominal GDP) and most powerful military. Involvement in foreign wars has resulted in over 620,000 further U.S. fatalities since the Civil War, and migration fell drastically during the World Wars and Great Depression; however the population continuously grew in these years as the total fertility rate remained above two births per woman, and life expectancy increased (except during the Spanish Flu pandemic of 1918).

Since the Second World War, Latin America has replaced Europe as the most common point of origin for migrants, with Hispanic populations growing rapidly across the south and border states. Because of this, the proportion of non-Hispanic whites, which has been the most dominant ethnicity in the U.S. since records began, has dropped more rapidly in recent decades. Ethnic minorities also have a much higher birth rate than non-Hispanic whites, further contributing to this decline, and the share of non-Hispanic whites is expected to fall below fifty percent of the U.S. population by the mid-2000s. In 2020, the United States has the third-largest population in the world (after China and India), and the population is expected to reach four hundred million in the 2050s.

In the United Kingdom, the crude birth rate in 1800 was 37 live births per thousand people, meaning that 3.7 percent of the population had been born in that year. From 1800 until 1830, the crude birth rate jumped between 35 and 45, before plateauing between 35 and 37 until the 1880s. From 1880 until the Second World War, the crude birth rate dropped to just under fifteen births per one thousand people, with the only increase coming directly after World War One. After WWII, the United Kingdom experienced a baby boom, as many soldiers returned home and the economy recovered, however this boom stopped in the late 1960s and the crude birth rate went into decline again. From the late 1970s until today, the crude birth rate has remained between eleven and fourteen, and is expected to be 11.5 in 2020.

It is estimated that Europe had an urbanization rate of approximately 8.5 percent in the year 1800. The Netherlands and Belgium were some of the most heavily urbanized regions, due the growth of port cities such as Rotterdam and Antwerp during Netherlands' empirical expansion, and the legacy of urbanization in the region, which stems from its wool and craft industries in medieval times. Additionally, the decline of their agricultural sectors and smaller territories contributed to a lower rural population. Scotland and England had also become more urban throughout the British Empire's growth, although the agricultural revolution of the previous two centuries, along with the first industrial revolution, then led to more rapid urbanization during the 19th century. In contrast, there was a large imbalance between the east and west of the continent; the two largest empires, Austria and Russia, had the lowest levels of urbanization in Europe in 1800, due to their vast territories, lower maritime presence, and lack of industrial development.

The Census@Leicester datasets include socio-demographic data from the 2001, 2011, and 2021 Leicester censuses to enable the exploration of recent historical trends. It also includes data from the 2021 census for both Nottingham and Coventry to enable comparisons with other cities.

This online resource that can be used for teaching and research purposes by staff and students and to create a legacy for the Census@Leicester Project.

In 1800, the population of the region of present-day India was approximately 169 million. The population would grow gradually throughout the 19th century, rising to over 240 million by 1900. Population growth would begin to increase in the 1920s, as a result of falling mortality rates, due to improvements in health, sanitation and infrastructure. However, the population of India would see it’s largest rate of growth in the years following the country’s independence from the British Empire in 1948, where the population would rise from 358 million to over one billion by the turn of the century, making India the second country to pass the billion person milestone. While the rate of growth has slowed somewhat as India begins a demographics shift, the country’s population has continued to grow dramatically throughout the 21st century, and in 2020, India is estimated to have a population of just under 1.4 billion, well over a billion more people than one century previously. Today, approximately 18% of the Earth’s population lives in India, and it is estimated that India will overtake China to become the most populous country in the world within the next five years.

Abstract copyright UK Data Service and data collection copyright owner.

The Integrated Census Microdata (I-CeM), England and Wales, 1921 study contains the standardised England and Wales data for 1921.

The Integrated Census Microdata (I-CeM) project has produced a standardised, integrated dataset of most of the censuses of Great Britain for the period 1851 to 1911: England and Wales for 1851-1861, 1881-1921 and Scotland for 1851-1901, and 1921 making available to academic researchers, detailed information at parish level about everyone resident in Great Britain collected at most of the decennial censuses between 1851-1921.

The name and address details for individuals are not currently included in the database; for reasons of commercial sensitivity, these are held under Special Licence access conditions under SN 9281 Integrated Census Microdata (I-CeM) Names and Addresses, England and Wales, 1921: Special Licence Access. See the catalogue record for 9281 for instructions on how to apply for those data.

These data are available via an online system at https://icem.ukdataservice.ac.uk/

Further information about I-CeM can be found on the I-CeM Integrated Microdata Project webpages.

The data contain information on age, gender, household structure and composition, occupation, employer, place of work, education, marital status, birthplace and nationality. Further details are also available for those enumerated in institutions (including vessels and barracks).

Reconstitutions of families from historical parish register baptism, marriage and burial entries of individuals in 26 English parishes (Alcester, Aldenham, Ash, Austrey, Banbury, Birstall, Bottesford, Bridford, Colyton, Dawlish, Earsdon, Gainsborough, Gedling, Great Oakley, Hartland, Ipplepen, Lowestoft, March, Methley, Morchard Bishop, Odiham, Reigate, Shepshed, Southill, Terling and Willingham). These data formed the empirical basis for the population history of England presented in: EA Wrigley, RS Davies, JE Oeppen and RS Schofield: 'English Population History from Family Reconstitution: 1580-1837' (Cambridge University Press, 1997).

Using families reconstructed from baptism, burial and marriage records from Anglican parish registers as a national population sample to explore the demographic history of England. This included detailed studies of fertility, mortality and nuptiality, and refinements to previous estimates of population size and structure.

1. Predicting how populations may respond to climate change and anthropogenic pressures requires detailed knowledge of demographic traits, such as survival and reproduction. However, the availability of these data varies greatly across space and taxa. Therefore, it is common practice to conduct population assessments by filling in missing values from surrogate species or other populations of the same species. Using these independent surrogate values concurrently with observed data neglects the life‐history trade‐offs that connect the different aspects of a population's demography. Consequently, this approach introduces biases that could ultimately lead to erroneous management decisions. 2. We use a Bayesian hierarchical framework to combine fragmented multi‐population data with established life‐history theory and reconstruct population‐specific demographic data across a substantial part of a species breeding range. We apply our analysis to a long‐lived colonial species, the black‐legged kittiwake Rissa tridactyla, that is classified as globally Vulnerable and is highly threatened by increasing anthropogenic pressures, including offshore renewable energy development. We then use a projection analysis to examine how the reconstructed demographic parameters may improve population assessments, compared to models that combine observed data with independent surrogate values. 3. Demographic parameters reconstructed using a hierarchical framework can be utilised in a range of population modelling approaches. They can also be used as reference estimates to assess whether independent surrogate values are likely to over or underestimate missing demographic parameters. We show that surrogate values from independent sources are often used to fill in missing parameters that have large potential demographic impact, and that resulting biases are driven in unpredictable directions thus precluding assessments from being consistently precautionary. 4. Synthesis and applications. Our study dramatically increases the spatial coverage of population‐specific demographic data for black‐legged kittiwakes. The reconstructed demographic parameters presented can also be used immediately to reduce uncertainty in the consenting process for offshore wind development in the United Kingdom and Ireland. More broadly, we show that the reconstruction approach used here provides a new avenue for improving evidence‐based management and policy action for animal and plant populations with fragmented and error prone demographic data. 22-Mar-2021

Methods JAGS code and data for the correlated model. The script was written using JAGS (v. 4.3.0) via the “jagsUI” library (v 1.5.1) for program R (v. 4.0.2). It runs a Bayesian hierarchical model (“correlated model”) to reconstruct mean rates of adult survival and fecundity for 68 populations of black-legged kittiwake breeding in the UK and Ireland. Input data supplied. See Table S1 in the Supplementary Information for additional details on data sources.

The earliest point where scientists can make reasonable estimates for the population of global regions is around 10,000 years before the Common Era (or 12,000 years ago). Estimates suggest that Asia has consistently been the most populated continent, and the least populated continent has generally been Oceania (although it was more heavily populated than areas such as North America in very early years). Population growth was very slow, but an increase can be observed between most of the given time periods. There were, however, dips in population due to pandemics, the most notable of these being the impact of plague in Eurasia in the 14th century, and the impact of European contact with the indigenous populations of the Americas after 1492, where it took almost four centuries for the population of Latin America to return to its pre-1500 level. The world's population first reached one billion people in 1803, which also coincided with a spike in population growth, due to the onset of the demographic transition. This wave of growth first spread across the most industrially developed countries in the 19th century, and the correlation between demographic development and industrial or economic maturity continued until today, with Africa being the final major region to begin its transition in the late-1900s.

Abstract copyright UK Data Service and data collection copyright owner.

This collection represents the data used to reconstruct the pre-Census population history of England by Wrigley and Schofield, in restructured form. It consists of counts of parish register events from 404 English sample parishes. These data were originally used to estimate national totals of births, deaths and marriages. From these population growth rates were derived and hence the overall English population in each year between 1539 and 1836, but these data are also relevant for local studies of particular parishes or regions, and for studies of mortality variations and crises, which was the purpose for which this restructuring was undertaken. This data collection contains tab-delimited text files of monthly and annual historical counts of baptisms, marriages and burials from parish registers in 404 English parishes, with missing data interpolated, for varying coverage periods in each parish, including a core period of 1662 to 1811.

Volunteer local historians counted events from accessible parish registers with apparently good coverage, from a list distributed by Tony Wrigley at CAMPOP. Counts were recorded on paper pro formas. These were digitised many years ago by CAMPOP into the Population History of England database. Quality checking of count accuracy per volunteer was performed by Roger Schofield and inaccurate contributions discarded. In their current restructured form these files were derived by Gill Newton at CAMPOP from the Population History of England database.

Population, baptisms, marriages, burials, mortality, nuptiality, fertility, historical demography.

Abstract copyright UK Data Service and data collection copyright owner.

This Special Licence Access dataset contains names and addresses from the Integrated Census Microdata (I-CeM) dataset for England and Wales for 1921. These data are made available under Special Licence (SL) access conditions due to commercial sensitivity.

The anonymised main I-CeM database that complements these names and addresses is available under End User Licence access: SN 9281, Integrated Census Microdata (I-CeM), England and Wales, 1921. See the catalogue record for 9280 for details on how to access the EUL data.

Further information about I-CeM can be found on the I-CeM Integrated Microdata Project and webpages.

File format

These data are available in delimited .txt format. Due to the size of the file, it has been zipped in '.7z' format to ease download delivery. The file can be easily unzipped using open-source 7-Zip software or similar packages. Users may need to take advice from their organisation's IT service.

This dataset contains information on life history variation and population dynamics in response to coloured environmental variation in the laboratory model system comprised of the moth Plodia interpunctella (Pyralidae; Hübner) and the parasitoid wasp Venturia canescens (Ichneumonidae; Gravenhorst). Data were collected from two complementary experiments investigating the effects of daily coloured temperature fluctuations on individual life history variation (single-generation life history experiment) and population dynamics (multi-generation microcosm experiment) in both species. In both experiments, the effects of three types of coloured noise were investigated and compared to constant temperature conditions: blue noise (characterized by rapid (negatively autocorrelated) fluctuations), red noise (characterized by slow (positively autocorrelated) fluctuations) and white noise (characterized by random fluctuations). The life history experiment lasted 56 days and the microcosm experiment lasted 310 days.

This dataset provides Census 2021 estimates for Employment history in Northern Ireland. The estimates are as at census day, 21 March 2021.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

The quality assurance report can be found here

[This dataset is embargoed until December 1, 2020]. Data comprise monitoring records of a population of Gryllus campestris, a flightless, univoltine field cricket that lives in and around burrows excavated among the grass in a meadow in Asturias (North Spain). The area has an altitude range from around 60 to 270 metres above sea level. Data include basic traits, behavioural data, genotypes and pheromones. Data were collected from 2006 to 2016. Full details about this dataset can be found at https://doi.org/10.5285/42d9fc5d-f30e-46a9-9d09-50272f4538cb

BackgroundThe ageing population poses a tremendous challenge in understanding the sources of inequalities in health. Though they appear to be far removed, childhood conditions are known to be inextricably linked with adult health, and in turn on health in later life. The long arm of childhood conditions hypothesis is often tested using recollection of childhood circumstances, but such subjective recall can yield potentially inaccurate or possibly biased inferences. We tested the long arm hypothesis on three outcomes in later life, arrayed from objective to subjective health, namely: gait speed, episodic memory and mental health.Methods and FindingsWe used the English Longitudinal Study of Ageing 2006 enriched with retrospective life history (N = 5,913). To deal with recall problems two solutions, covariate measurement and endogenous treatment models, were applied. Retrospective childhood material lack includes growing up without running hot or cold water, fixed bath, indoor lavatory and central heating. Adjustment is made for an extensive set of confounders including sex, age, adult health, wealth, education, occupation, social support, social connections, chronic conditions, smoking, drinking, and physical exercise. It is found that material poverty when growing up shows no association with health when growing old, assuming accurate recall. Once recall problems are controlled, we found that childhood material poverty changes inversely with later life health.ConclusionA poorer childhood goes with slower gait, poorer memory and more depression in later life. This result provides a further impetus to eliminate child poverty.

In 1800, the region of Germany was not a single, unified nation, but a collection of decentralized, independent states, bound together as part of the Holy Roman Empire. This empire was dissolved, however, in 1806, during the Revolutionary and Napoleonic eras in Europe, and the German Confederation was established in 1815. Napoleonic reforms led to the abolition of serfdom, extension of voting rights to property-owners, and an overall increase in living standards. The population grew throughout the remainder of the century, as improvements in sanitation and medicine (namely, mandatory vaccination policies) saw child mortality rates fall in later decades. As Germany industrialized and the economy grew, so too did the argument for nationhood; calls for pan-Germanism (the unification of all German-speaking lands) grew more popular among the lower classes in the mid-1800s, especially following the revolutions of 1948-49. In contrast, industrialization and poor harvests also saw high unemployment in rural regions, which led to waves of mass migration, particularly to the U.S.. In 1886, the Austro-Prussian War united northern Germany under a new Confederation, while the remaining German states (excluding Austria and Switzerland) joined following the Franco-Prussian War in 1871; this established the German Empire, under the Prussian leadership of Emperor Wilhelm I and Chancellor Otto von Bismarck. 1871 to 1945 - Unification to the Second World War The first decades of unification saw Germany rise to become one of Europe's strongest and most advanced nations, and challenge other world powers on an international scale, establishing colonies in Africa and the Pacific. These endeavors were cut short, however, when the Austro-Hungarian heir apparent was assassinated in Sarajevo; Germany promised a "blank check" of support for Austria's retaliation, who subsequently declared war on Serbia and set the First World War in motion. Viewed as the strongest of the Central Powers, Germany mobilized over 11 million men throughout the war, and its army fought in all theaters. As the war progressed, both the military and civilian populations grew increasingly weakened due to malnutrition, as Germany's resources became stretched. By the war's end in 1918, Germany suffered over 2 million civilian and military deaths due to conflict, and several hundred thousand more during the accompanying influenza pandemic. Mass displacement and the restructuring of Europe's borders through the Treaty of Versailles saw the population drop by several million more.

Reparations and economic mismanagement also financially crippled Germany and led to bitter indignation among many Germans in the interwar period; something that was exploited by Adolf Hitler on his rise to power. Reckless printing of money caused hyperinflation in 1923, when the currency became so worthless that basic items were priced at trillions of Marks; the introduction of the Rentenmark then stabilized the economy before the Great Depression of 1929 sent it back into dramatic decline. When Hitler became Chancellor of Germany in 1933, the Nazi government disregarded the Treaty of Versailles' restrictions and Germany rose once more to become an emerging superpower. Hitler's desire for territorial expansion into eastern Europe and the creation of an ethnically-homogenous German empire then led to the invasion of Poland in 1939, which is considered the beginning of the Second World War in Europe. Again, almost every aspect of German life contributed to the war effort, and more than 13 million men were mobilized. After six years of war, and over seven million German deaths, the Axis powers were defeated and Germany was divided into four zones administered by France, the Soviet Union, the UK, and the U.S.. Mass displacement, shifting borders, and the relocation of peoples based on ethnicity also greatly affected the population during this time. 1945 to 2020 - Partition and Reunification In the late 1940s, cold war tensions led to two distinct states emerging in Germany; the Soviet-controlled east became the communist German Democratic Republic (DDR), and the three western zones merged to form the democratic Federal Republic of Germany. Additionally, Berlin was split in a similar fashion, although its location deep inside DDR territory created series of problems and opportunities for the those on either side. Life quickly changed depending on which side of the border one lived. Within a decade, rapid economic recovery saw West Germany become western Europe's strongest economy and a key international player. In the east, living standards were much lower, although unemployment was almost non-existent; internationally, East Germany was the strongest economy in the Eastern Bloc (after the USSR), though it eventually fell behind the West by the 1970s. The restriction of movement between the two states also led to labor shortages in t...