In 2024, Millennials were the largest generational cohort in the United Kingdom, comprising approximately 21.7 percent of the population. Gen X was the next largest generation at 20.3 percent of the population, followed by Gen Z at 19.6 percent, and the Baby Boomer Generation on 19.3 percent. People belonging to earlier generations accounted for just 5.9 percent of the UK's population in this year.

In 2024, there were approximately ** million millennials in the United Kingdom, making it the largest generational cohort at that time. Millennials surpassed the Baby Boomer generation as the largest generation for the first time in 2019. The two youngest generations, Gen Z and Gen Alpha, numbered approximately **** million, and ****million respectively. Gen X are, as of the most recent year, the second-largest generation in the UK at ** million people. The population born before the end of the Second World War in mid-1945 was just over **** million in this year. Post-War Baby Boom The baby boomer generation was the largest generation for much of this period due to the spike in births that happened after the Second World War. In 1947, for example, there were over *** million live births in the United Kingdom, compared with just ******* live births just thirty years later in 1977. Members of this generation are typically the parents of millennials, and were the driving force behind the countercultural movement of the 1960s, due to their large numbers relative to older generations at the time. The next generational cohort after Boomers are Generation X, born between 1965 and 1980. This generation had fewer members than the Boomer generation for most of its existence, and only became larger than it in 2021. Millennials and Gen Z As of 2024, the most common single year of age in the United Kingdom was 33, with approximately ******* people this age. Furthermore, people aged between 30 and 34 were the most numerous age group in this year, at almost *** million people. As of 2024, people in this age group were Millennials, the large generation who came of age in the late 1990s and early 2000s. Many members of this generation entered the workforce following the 2008 financial crash, and suffered through high levels of unemployment during the early 2010s. The generation that followed Millennials, Generation Z, have also experienced tough socio-economic conditions recently, with key formative years dominated by the COVID-19 pandemic, climate change, and an increasingly unstable geopolitical situation.

There were almost 4.8 million people aged between 30 and 34 in the United Kingdom in 2024, making it the most populous age group in that year. Those aged between 35 and 39 years comprised the next most numerous age group in this year, at over 4.78 million people. Millennials overtake Boomers as biggest generation Post-war demographic trends, particularly the 'baby boom' phenomenon, have significantly influenced the current age distribution in the UK. The postwar peak of live births in 1947 resulted in the dominance of the Baby Boomer generation for several decades, until 2020 when Millennials became the largest generational cohort, surpassing the Boomers for the first time. The following year, the UK Boomer population was then overtaken by Generation X, the generation born between Boomers and Millennials. Generation Z, remained smaller than the three generations that preceded it until 2024 when there were more Gen Zers than Boomers. Aging UK population poses challenges The median age of the UK population is projected to reach 44.5 years by 2050, compared to 34.9 years in 1950. This aging trend is indicative of broader global demographic shifts, with the median age of people worldwide forecasted to increase from 23.6 years in 1950 to 41.9 years by 2100. How countries like the UK manage their aging populations will be one of the key challenges of the next few decades. It is likely the UK's struggling National Health Service (NHS) will come under even more pressure in the coming years. There are also tough economic questions, in particular as more people enter retirement age and the UK's working population gets smaller in relation to it.

There were over 15 million millennials in the United Kingdom in 2024. This generation, sometimes called Generation Y were born between 1981 and 1996 and are mainly the children of the post-war Baby Boomer generation. As of 2024, Millennials were the largest generational cohort in the UK, followed by Generation X at 14 million people, Gen Z at 13.6 million, and then the Baby Boomer generation at 13.4 million. The most numerous single-year of age for Millennials, and the UK as a whole, was 33 at over 976,000. Boomerang generation The first cohort of millennials came of age at the turn of the century and have almost certainly been heavily influenced by the growth of internet accessibility during this time. The economic challenges faced by this generation may have a relation to the increasing share of young adults who live with their parents in the UK. This has led to the perhaps unfair, characterization of millennials as the boomerang generation, who failed to grow-up and mature. Some of these negative stereotypes regarding Millennials have since shifted to the next youngest generation, Generation Z, who entered the workplace in the mid-2010s. Generation Remain One of the main challenges that British millennials currently face are their prospects after Brexit. Although the United Kingdom voted to leave the European Union in June 2016, there were clear divisions between regions, classes and age-groups. Most millennials voted to remain in the Brexit referendum, with 73 percent of people aged 18 to 24, and 62 percent of those aged 25 to 34 voting to remain. As of October 2025, around a quarter of 25 to 49-year-olds intended to vote for the Labour Party, the same who would vote for the insurgent Reform Party, currently riding high in opinion polls. Millennials still appear to oppose Brexit, with approximately 69 percent of 25 to 49-year-olds believing Brexit to have been the wrong decision.

Principal projection for the UK - population by five-year age groups and sex.

National and subnational mid-year population estimates for the UK and its constituent countries by administrative area, age and sex (including components of population change, median age and population density).

As of 2024, the estimated population of Gen Z in the United Kingdom was 13.6 million, ranging from 12 to 27-year's old. The most-common single year of age for Gen Z in this year was 27, at 923,421, while there were 806,916 that were aged 18, the least common year of age.

In 2024, there were estimated to be 976,481 people who were aged 33 in the United Kingdom, the most of any age in this year. The two largest age groups during this year were 30-34, and 35-39, at 4.8 million and 4.78 million people respectively. There is also a noticeable spike of 673,831 people who were aged 77, which is due to the high number of births that followed the end of the Second World War. Over one million born in 1964 In post-war Britain, there have only been two years when the number of live births was over one million, in 1947 and in 1964. The number of births recorded in the years between these two years was consistently high as well, with 1955 having the fewest births in this period at 789,000. This meant that until relatively recently, Baby Boomers were the largest generational cohort in the UK. As of 2024, there were approximately 13.4 million Baby Boomers, compared with 14 million in Generation X, 15 million Millennials, and 13.6 million members of Gen Z. The youngest generation in the UK, Generation Alpha, numbered approximately 9.2 million in the same year. Median age to hit 44.5 years by 2050 The population of the United Kingdom is aging at a substantial rate, with the median age of the population expected to reach 44.5 years by 2050. By comparison, in 1950 the average age in the United Kingdom stood at 34.9 years. This phenomenon is not unique to the United Kingdom, with median age of people worldwide increasing from 23.6 years in 1950 to a forecasted 41.9 years by 2100. As of 2024, the region with the oldest median age in the UK was South West England, at 43.7 years, compared with 35.7 in London, the region with the youngest median age.

The mid-year estimates refer to the population on 30 June of the reference year and are produced in line with the standard United Nations (UN) definition for population estimates. They are the official set of population estimates for the UK and its constituent countries, the regions and counties of England, and local authorities and their equivalents.

Office for National Statistics’ national and subnational mid-year population estimates for England and Wales for a selection of administrative and census areas by additional useful age for 2012 to 2020. Age categories include: 0-15, 5-11, 11-15, 16-17, 16-29, 16-64, 18-24, 30-44, 45-64, 65+ & 70+. The data is source is from ONS Population Estimates. Find out more about this dataset here.

This data is issued at (BGC) Generalised (20m) boundary type for:

Country, Region, Upper Tier Local Authority (2021), Lower Tier Local Authority (2021), Middle Super Output Area (2011), and Lower Super Output Area (2011).

If you require the data at full resolution boundaries, or if you are interested in the range of statistical data that Esri UK make available in ArcGIS Online please enquire at dataenquiries@esriuk.com.

The Office for National Statistics (ONS) produces annual estimates of the resident population of England and Wales at 30 June every year. The most authoritative population estimates come from the census, which takes place every 10 years in the UK. Population estimates from a census are updated each year to produce mid-year population estimates (MYEs), which are broken down by local authority, sex and age. More detailed information on the methods used to generate the mid-year population estimates can be found here.

For further information on the usefulness of the data and guidance on small area geographies please see here.The currency of this data is 2021.

Methodology

The total and 5-year breakdown population counts are reproduced directly from the source data. The age range estimates have been calculated from the published estimates by single year of age. The percentages are calculated using the gender specific (total, female or male) total population count as a denominator except in the case of the male and female total population where the total population is used to give female and male proportions.

This dataset will be updated annually, in two releases.

Creator: Office for National Statistics. Aggregated age groupings and percentages calculated by Esri UK._The data services available from this page are derived from the National Data Service. The NDS delivers thousands of open national statistical indicators for the UK as data-as-a-service. Data are sourced from major providers such as the Office for National Statistics, Public Health England and Police UK and made available for your area at standard geographies such as counties, districts and wards and census output areas. This premium service can be consumed as online web services or on-premise for use throughout the ArcGIS system.Read more about the NDS.

This dataset contains information on estimates of the usual resident population in the UK as of 30 June 2016 by age and gender; the data is from the local authorities.

As of 2024, there were just over 14 million members of Generation X in the United Kingdom, ranging from the ages of 44 to 59. The most-common single year of age for Gen X in this year was 53, at 927,472, while there were 790,242 47 year-old's, the least common year of age.

Low population variant projection for the UK - population by five-year age groups and sex.

United Kingdom UK: Age Dependency Ratio: % of Working-Age Population: Old data was reported at 29.037 % in 2017. This records an increase from the previous number of 28.659 % for 2016. United Kingdom UK: Age Dependency Ratio: % of Working-Age Population: Old data is updated yearly, averaging 23.904 % from Dec 1960 (Median) to 2017, with 58 observations. The data reached an all-time high of 29.037 % in 2017 and a record low of 18.068 % in 1960. United Kingdom UK: Age Dependency Ratio: % of Working-Age Population: Old data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s United Kingdom – Table UK.World Bank.WDI: Population and Urbanization Statistics. Age dependency ratio, old, is the ratio of older dependents--people older than 64--to the working-age population--those ages 15-64. Data are shown as the proportion of dependents per 100 working-age population.; ; World Bank staff estimates based on age distributions of United Nations Population Division's World Population Prospects: 2017 Revision.; Weighted average;

Population ages 65 and above, total in United Kingdom was reported at 13498909 Persons in 2024, according to the World Bank collection of development indicators, compiled from officially recognized sources. United Kingdom - Total Population for Age 65 and above (only 2005 and 2010) (in number of people) - actual values, historical data, forecasts and projections were sourced from the World Bank on February of 2026.

Mid-year estimates of resident population for the respective calendar years, based on the 2001 Census by age and sex. The estimated resident population of an area includes all people who usually live there, whatever their nationality. Members of UK and non-UK armed forces stationed in the UK are included and UK forces stationed outside the UK are excluded. Students are taken to be resident at their term time address. To facilitate planning of health services at local level and provide denominators for epidemiological analyses. Legacy unique identifier: P00006

The census is undertaken by the Office for National Statistics every 10 years and gives us a picture of all the people and households in England and Wales. The most recent census took place in March of 2021.The census asks every household questions about the people who live there and the type of home they live in. In doing so, it helps to build a detailed snapshot of society. Information from the census helps the government and local authorities to plan and fund local services, such as education, doctors' surgeries and roads.Key census statistics for Leicester are published on the open data platform to make information accessible to local services, voluntary and community groups, and residents.Further information about the census and full datasets can be found on the ONS website - https://www.ons.gov.uk/census/aboutcensus/censusproducts

Graph and download economic data for Infra-Annual Labor Statistics: Working-Age Population Total: From 15 to 64 Years for United Kingdom (LFWA64TTGBQ647N) from Q2 1992 to Q4 2025 about working-age, 15 to 64 years, United Kingdom, and population.

United Kingdom UK: Population: Male: Ages 20-24: % of Male Population data was reported at 6.397 % in 2017. This records a decrease from the previous number of 6.504 % for 2016. United Kingdom UK: Population: Male: Ages 20-24: % of Male Population data is updated yearly, averaging 7.006 % from Dec 1960 (Median) to 2017, with 58 observations. The data reached an all-time high of 8.797 % in 1986 and a record low of 6.102 % in 2000. United Kingdom UK: Population: Male: Ages 20-24: % of Male Population data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s United Kingdom – Table UK.World Bank.WDI: Population and Urbanization Statistics. Male population between the ages 20 to 24 as a percentage of the total male population.; ; World Bank staff estimates based on age/sex distributions of United Nations Population Division's World Population Prospects: 2017 Revision.; ;