Life expectancy in the United Kingdom was below 39 years in the year 1765, and over the course of the next two and a half centuries, it is expected to have increased by more than double, to 81.1 by the year 2020. Although life expectancy has generally increased throughout the UK's history, there were several times where the rate deviated from its previous trajectory. These changes were the result of smallpox epidemics in the late eighteenth and early nineteenth centuries, new sanitary and medical advancements throughout time (such as compulsory vaccination), and the First world War and Spanish Flu epidemic in the 1910s.

In 2022 life expectancy for both males and females at birth fell when compared to 2021. Male life expectancy fell from 78.71 years to 78.57 years, and from 82.68 years to 82.57 years for women.

It is only in the past two centuries where demographics and the development of human populations has emerged as a subject in its own right, as industrialization and improvements in medicine gave way to exponential growth of the world's population. There are very few known demographic studies conducted before the 1800s, which means that modern scholars have had to use a variety of documents from centuries gone by, along with archeological and anthropological studies, to try and gain a better understanding of the world's demographic development. Genealogical records One such method is the study of genealogical records from the past; luckily, there are many genealogies relating to European families that date back as far as medieval times. Unfortunately, however, all of these studies relate to families in the upper and elite classes; this is not entirely representative of the overall population as these families had a much higher standard of living and were less susceptible to famine or malnutrition than the average person (although elites were more likely to die during times of war). Nonetheless, there is much to be learned from this data. Impact of the Black Death In the centuries between 1200 and 1745, English male aristocrats who made it to their 21st birthday were generally expected to live to an age between 62 and 72 years old. The only century where life expectancy among this group was much lower was in the 1300s, where the Black Death caused life expectancy among adult English noblemen to drop to just 45 years. Experts assume that the pre-plague population of England was somewhere between four and seven million people in the thirteenth century, and just two million in the fourteenth century, meaning that Britain lost at least half of its population due to the plague. Although the plague only peaked in England for approximately eighteen months, between 1348 and 1350, it devastated the entire population, and further outbreaks in the following decades caused life expectancy in the decade to drop further. The bubonic plague did return to England sporadically until the mid-seventeenth century, although life expectancy among English male aristocrats rose again in the centuries following the worst outbreak, and even peaked at more than 71 years in the first half of the sixteenth century.

A global phenomenon, known as the demographic transition, has seen life expectancy from birth increase rapidly over the past two centuries. In pre-industrial societies, the average life expectancy was around 24 years, and it is believed that this was the case throughout most of history, and in all regions. The demographic transition then began in the industrial societies of Europe, North America, and the West Pacific around the turn of the 19th century, and life expectancy rose accordingly. Latin America was the next region to follow, before Africa and most Asian populations saw their life expectancy rise throughout the 20th century.

The dataset was originally created to allow the construction of age-specific mortality series and cohort mortality series for particular diseases, from the mid-nineteenth century to the present (in conjunction with the comparable mortality database created by the Office of National Statistics which covers 1901 – present). The dataset is fairly comprehensive and therefore allows both fine analysis of trends in single causes and also the construction of consistent aggregated categories of causes over time. Additionally, comparison of trends in individual causes can be used to infer transfers of deaths between categories over time, that may cause artifactual changes in mortality rates of particular causes. The data are presented by sex, allowing calculation of sex ratios. The age-specific and annual nature of the dataset allows the analysis of cause-specific mortality by birth cohort (assuming low migration at the national level). The database can be used in conjunction with the ONS database “Historic Mortality and Population Data, 1901-1992”, already in the UK Data Archive collection as SN 2902, to create continuous cause-of-death series for the period 1848-1992 (or later, if using more recent versions of the ONS database).

At the beginning of the 1840s, life expectancy from birth in Ireland was just over 38 years. However, this figure would see a dramatic decline with the beginning of the Great Famine in 1845, and dropped below 21 years in the second half of the decade (in 1849 alone, life expectancy fell to just 14 years). The famine came as a result of a Europe-wide potato blight, which had a disproportionally devastating impact on the Irish population due to the dependency on potatoes (particularly in the south and east), and the prevalence of a single variety of potato on the island that allowed the blight to spread faster than in other areas of Europe. Additionally, authorities forcefully redirected much of the country's surplus grain to the British mainland, which exacerbated the situation. Within five years, mass starvation would contribute to the deaths of over one million people on the island, while a further one million would emigrate; this also created a legacy of emigration from Ireland, which saw the population continue to fall until the mid-1900s, and the total population of the island is still well below its pre-famine level of 8.5 million people.

Following the end of the Great Famine, life expectancy would begin to gradually increase in Ireland, as post-famine reforms would see improvements in the living standards of the country’s peasantry, most notably the Land Wars, a largely successful series of strikes, boycotts and protests aimed at reform of the country's agricultural land distribution, which began in the 1870s and lasted into the 20th century. As these reforms were implemented, life expectancy in Ireland would rise to more than fifty years by the turn of the century. While this rise would slow somewhat in the 1910s, due to the large number of Irish soldiers who fought in the First World War and the Spanish Flu pandemic, as well as the period of civil unrest leading up to the island's partition in 1921, life expectancy in Ireland would rise greatly in the 20th century. In the second half of the 20th century, Ireland's healthcare system and living standards developed similarly to the rest of Western Europe, and today, it is often ranks among the top countries globally in terms of human development, GDP and quality of healthcare. With these developments, the increase in life expectancy from birth in Ireland was relatively constant in the first century of independence, and in 2020 is estimated to be 82 years.

Life expectancy in India was 25.4 in the year 1800, and over the course of the next 220 years, it has increased to almost 70. Between 1800 and 1920, life expectancy in India remained in the mid to low twenties, with the largest declines coming in the 1870s and 1910s; this was because of the Great Famine of 1876-1878, and the Spanish Flu Pandemic of 1918-1919, both of which were responsible for the deaths of up to six and seventeen million Indians respectively; as well as the presence of other endemic diseases in the region, such as smallpox. From 1920 onwards, India's life expectancy has consistently increased, but it is still below the global average.

The statistic depicts the median age of the population in the United Kingdom from 1950 to 2100*. The median age of a population is an index that divides the population into two equal groups: half of the population is older than the median age and the other half younger. In 2020, the median age of United Kingdom's population was 39.2 years. Population of the United Kingdom The United Kingdom (UK) includes Great Britain (England, Scotland and Wales) and Northern Ireland, and is a state located off the coast of continental Europe. The United Kingdom is a constitutional monarchy, which means the Queen acts as representative head of state, while laws and constitutional issues are discussed and passed by a parliament. The total UK population figures have been steadily increasing, albeit only slightly, over the last decade; in 2011, the population growth rate was lower than in the previous year for the first time in eight years. Like many other countries, the UK and its economy were severely affected by the economic crisis in 2009. Since then, the unemployment rate has doubled and is only recovering slowly. UK inhabitants tend to move to the cities to find work and better living conditions; urbanization in the United Kingdom has been on the rise. At the same time, population density in the United Kingdom has been increasing due to several factors, for example, the rising number of inhabitants and their life expectancy at birth, an increasing fertility rate, and a very low number of emigrants. In fact, the United Kingdom is now among the 20 countries with the highest life expectancy at birth worldwide. As can be seen above, the median age of UK residents has also been increasing significantly since the seventies; another indicator for a well-working economy and society.

In 1865, the average person born in Bangladesh could expect to live to just over the age of 25 years old. This figure would gradually decline throughout the remainder of the 19th century, falling to just over 20 years by 1900, as the Bengal region of British Raj would see several severe famines in this time period. However, life expectancy would begin to increase gradually in the early 1900s, outside of a small decline in the late 1910s from the 1918 Spanish Flu epidemic. Beginning in the 1930s, life expectancy in Bangladesh would begin to grow rapidly, as wartime exports and industrialization would lead to significant improvements in standards of living in the region. This growth would continue steadily throughout the rest of the century, declining only with the Bangladesh War of Independence in 1971. As access to and quality of healthcare in Bangladesh continuously improves, in 2020, the average person born in Bangladesh can expect to live to just over the age of 72 years old, which is higher than most other countries on the Indian subcontinent.

Between 1953 and 2021, the death rate of the United Kingdom fluctuated between a high of 12.2 deaths per 1,000 people in 1962 and a low of 8.7 in 2011. From 2011 onwards, the death rate creeped up slightly and, in 2020, reached 10.3 deaths per 1,000 people. In 2021, the most recent year provided here, the death rate was ten, a decline from 2020 but still higher than in almost every year in the twenty-first century. The recent spike in the death rate corresponds to the emergence of the COVID-19 pandemic in the UK, with the first cases recorded in early 2020. Most deaths since 1918 in 2020 In 2020, there were 689,629 deaths in the United Kingdom, the highest in more than a century. Although there were fewer deaths in 2021, at 667,479, this was still far higher than in recent years. When looking at the weekly deaths in England and Wales for this time period, two periods stand out for reporting far more deaths than usual. The first period was between weeks 13 and 22 of 2020, which saw two weeks in late April report more than 20,000 deaths. Excess deaths for the week ending April 17, 2020, were 11,854, and 11,539 for the following week. Another wave of deaths occurred in January 2021, when there were more than 18,000 deaths per week between weeks three and five of that year. Improvements to life expectancy slowing Between 2020 and 2022, life expectancy in the United Kingdom was approximately 82.57 years for women and 78.57 years for men. Compared with life expectancy in 1980/82 this marked an increase of around six years for women and almost eight years for men. Despite these long-term developments, improvements to life expectancy have been slowing in recent years, and have declined since 2017/19. As of 2022, the country with the highest life expectancy in the World was Japan, which was 84.5 years, followed by South Korea, at 83.6 years.

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

There were 2,784 infant deaths in the United Kingdom in 2021, compared with 2,620 in the previous year. The number of infant deaths in 2020 was the fewest in the provided time period, especially compared with 1900 when there were 163,470 infant deaths.

There were 667,479 deaths in the United Kingdom in 2021, compared with 689,629 in 2020. Between 2003 and 2011, the annual number of deaths in the UK fell from 612,085 to just over 552,232. Since 2011 however, the annual number of annual deaths in the United Kingdom has steadily grown, with the number recorded in 2020, the highest since 1918 when there were 715,246 deaths. Both of these spikes in the number of deaths can be attributed to infectious disease pandemics. The great influenza pandemic of 1918, which was at its height towards the end of World War One, and the COVID-19 pandemic, which caused a large number of deaths in 2020.  Impact of the COVID-19 pandemic The weekly death figures for England and Wales highlight the tragic toll of the COVID-19 pandemic. In two weeks in April of 2020, there were 22,351 and 21,997 deaths respectively, almost 12,000 excess deaths in each of those weeks. Although hospitals were the most common location of these deaths, a significant number of these deaths also took place in care homes, with 7,911 deaths taking place in care homes for the week ending April 24, 2020, far higher than usual. By the summer of 2020, the number of deaths in England and Wales reached more usual levels, before a second wave of excess deaths hit the country in early 2021. Although subsequent waves of COVID-19 cases resulted in far fewer deaths, the number of excess deaths remained elevated throughout 2022. Long-term life expectancy trends As of 2022 the life expectancy for men in the United Kingdom was 78.57, and almost 82.57 for women, compared with life expectancies of 75 for men and 80 for women in 2002. In historical terms, this is a major improvement in relation to the mid 18th century, when the overall life expectancy was just under 39 years. Between 2011 and 2017, improvements in life expectancy in the UK did start to decline, and have gone into reverse since 2018/20. Between 2020 and 2022 for example, life expectancy for men in the UK has fallen by over 37 weeks, and by almost 23 weeks for women, when compared with the previous year.

The average age at which people in England and Wales get married has been rising since the 1970s, with the average age of men marrying women increasing from **** in 1972 to **** by 2019, with the average age for women marrying men going up from **** to **** in the same time period. Since 2014 and the legalization of same-sex marriage in England and Wales, the average age for men marrying men has fluctuated between **** and ****, while the average age for females marrying females has fluctuated between **** and ****. Strong support for same-sex marriage in UK Over ten years after same-sex marriage was legalized in most of the UK, polls have shown consistent support for the legislation. As of May 2025, ** percent of Britons supported same-sex marriage, compared with ** percent who opposed it, and ***** percent who did not know. England and Wales was the first jurisdiction to allow same-sex marriages, with the first marriages taking place in March 2014, followed by Scotland in December of that year. Legislation allowing same-sex marriage was not passed in Northern Ireland until 2019, with the first marriages not taking place in 2020. Most popular wedding dates In 2022, the most popular wedding date across the entire year in England and Wales was July 30, with ***** weddings taking place that day. The next most popular wedding date was August 20, which had ***** weddings, followed by May 28, at *****. All three of these dates were Saturday's, which, at over ** percent of all weddings, was by far the most popular day of the week for weddings to be held the week. As for the most popular month, August had the most weddings held in 2022, at ******, with ****** being held in July, and ****** in June, the second, and third-most popular months for weddings, respectively.

In 2021, the infant mortality rate in the United Kingdom was four deaths one year per 1,000 live births, one of the lowest infant mortality rate in this period. Infant mortality has fallen considerably since 1900, when there were 150 infant deaths per 1,000 live births.

The child mortality rate in the United Kingdom, for children under the age of five, was 329 deaths per thousand births in 1800. This means that approximately one in every three children born in 1800 did not make it to their fifth birthday. Over the course of the next 220 years, this number has dropped drastically, particularly in the first half of the twentieth century, and the rate has dropped to its lowest point ever in 2020 where it is just four deaths per thousand births.

In 2021 the live birth rate of the United Kingdom fell to 10.4 births per 1,000 population, the lowest it had been during this time period. The UK's birth rate has been declining steadily since 2010 when the birth rate was 12.9 births per 1,000 population. After 1938, the year with the highest birth rate in the UK was 1947, when the crude birth rate was 21.2 births per 1,000 population. Under two children per mother in 2021 The most recent crude live birth rate for this statistic is based on the 694,685 births, that occurred in 2021 as well as the mid-year population estimate of 67 million for the United Kingdom. It has a close relation to the fertility rate which estimates the average number of children women are expected to have in their lifetime, which was 1.53 in this reporting year. Among the constituent countries of the UK, Northern Ireland had the highest birth rate at 11.6, followed by England at 10.5, Wales at 9.3, and Scotland at 8.7. International comparisons The UK is not alone in seeing its birth and fertility rates decline dramatically in recent decades. Across the globe, fertility rates have fallen noticeably since the 1960s, with the fertility rate for Asia, Europe, and the Americas being below two in 2021. As of this year, the global fertility rate was 2.31, and was by far the highest in Africa, which had a fertility rate of 4.12, although this too has fallen from a high of 6.72 in the late 1960s. A reduction in infant mortality, as well as better access to contraception, are factors that have typically influenced declining fertility rates recently.

There were 694,685 live births recorded in the United Kingdom in 2021, compared with 681,560 in the previous year. Between 1887 and 2021 the year with the highest number of live births was 1920 when there were approximately 1.13 million births, while the year with the fewest births was 1977, when there were just 657,038 births. Birth rate at a historic low in 2020 At 10.2 births per 1,000 people, the birth rate of the United Kingdom in 2020 was at a historic low. After witnessing a twenty-first century high of 12.9 in 2010, the birth rate gradually declined before a sharp decrease was recorded between 2012 and 2013. Although there was a slight uptick in the birth rate in 2021, when there were 10.4 births per 1,000 people, the total fertility rate reached a low of 1.53 births per woman in the same year. As well as falling birth and fertility rates, the average age of mothers has been increasing. In 1991, the average age of mothers at childbirth was 27.7 years, compared with 30.9 years in 2021. UK population reaches 67 million In 2022, the overall population of the United Kingdom was almost 67.6 million people. Of the four countries that comprise the UK, England has by far the highest population, at 57.1 million, compared with 5.45 million in Scotland, 3.13 million in Wales, and 1.91 million in Northern Ireland. These countries are far less densely populated than England, especially when compared to London, which had approximately 5,630 people per square kilometer, compared with just 70 in Scotland. After London, North West England was the second-most densely populated area of the UK, which includes the large metropolitan areas of the cities of Manchester, and Liverpool

The fertility rate of a country is the average number of children that women from that country would have throughout their reproductive years. In the United Kingdom in 1800, the average woman of childbearing age would have five children over the course of their lifetime. Over the next 35 years the fertility rate was quite sporadic, rising to over 5.5 in the 1810s and 1820s, then dropping to 4.9 by 1835. This was during and after the Napoleonic Wars and the War of 1812 with the US, which was a time of increased industrialization, economic depression and high unemployment after the war. As things became more stable, and the 'Pax Britannica' (a period of relative, international peace and economic prosperity for the British Empire) came into full effect, the fertility rate plateaued until 1880, before dropping gradually until the First World War. The fertility rate then jumped from 2.6 to 3.1 children per woman between 1915 and 1920, as many men returned from the war. It then resumed it's previous trajectory in the interwar years, before increasing yet again after the war (albeit, for a much longer time than after WWI), in what is known as the 'Baby Boom'. Like the US, the Baby Boom lasted until around 1980, where it then fell to 1.7 children per woman, and it has remained around this number (between 1.66 and 1.87) since then.

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.