Overview of the UK population: January 2021

• In mid-2019, the population of the UK reached an estimated 66.8 million.

• The UK population's growth rate from mid-2018 to mid-2019, at 0.5%, was slower than any year since mid-2004.

• Between 2016 and 2019, long-term international immigration, emigration and net migration had remained broadly stable. However, in year ending December 2019 and year ending March 2020 (the latest data available), there was an increase in immigration and net migration.

• Migration has continued to be the main driver of the UK's population growth since the 1990s.

• It is projected that there will be an additional 7.5 million people aged 65 years and over in the UK in 50 years' time.

• Latest life expectancy figures show the slowdown in improvements seen since 2011 has continued; life expectancy at birth was 79.4 years for males and 83.1 years for females in the period 2017 to 2019.

This overview of the UK population covers the period of time directly before the coronavirus (COVID-19) pandemic in the UK, specifically 2019 for population statistics and up to March 2020 for migration statistics. We have recently published a blog on the possible effects of COVID-19 on the demography of the UK, as well as updates on information relating to the coronavirus situation.

This article uses the latest Long-Term International Migration estimates up to March 2020 and so does not reflect changes in migration resulting from substantial travel disruption and change since the start of the coronavirus (COVID-19) pandemic. In November 2020, we published an article bringing together available evidence on changes seen in international migration and mobility since the pandemic (up to September 2020). This included analysis of a range of administrative and survey data sources covering different topics such as overall travel to and from the UK and what we know about immigration for work or study.

Understanding the size and characteristics of the UK population is vital when it comes to planning and delivering services such as education, transport and healthcare. As the UK’s population continues to grow there has been a shift in the age structure towards older ages meaning we have an ageing population. In addition, our living arrangements are changing; more young adults are living with their parents and increasing numbers of people are living alone. This article brings together the main points from several of our publications to summarise how the UK’s population has changed.

The UK population has grown year-on-year since 1982 as seen in Figure 1. The 2019 mid-year population estimates release showed that the population of the UK reached 66.8 million, up from 66.4 million in mid-2018. This population growth marks an increase of 0.5%, or an additional 361,000 people, between mid-2018 and mid-2019. Growth in the year mid-2018 to mid-2019 was slower than in any year since mid-2004.

The UK population is projected to increase further; our 2018-based principal national population projections suggest the UK population will surpass 69.6 million by mid-2029 and reach 72 million by mid-2041 – increases of 4.2% and 7.8%, respectively, from mid-2019¹.

All four of the UK's constituent countries continue to contribute to the UK's annual growth. Northern Ireland’s population grew at a faster rate than the rest of the UK in the year to mid-2019. The contributions from all the four constituent countries are shown in Table 1.

Figure 2 displays the population growth rate of local authorities. By focusing on the overall growth over the past five years, any year-on-year fluctuations are smoothed out, enabling robust comparisons between areas.

Between mid-2014 and mid-2019, eight local authorities saw a growth in their population by 10% or more (Table 2). The four fastest-growing local authorities are in London, although the City of London has a relatively small population and so its growth rate can vary substantially from year to year.

Only 24 local authorities had a decrease in their population over the five-year period, of which 10 are located in Scotland. Many of these local authorities are in coastal areas with older populations, such as Inverclyde and North Ayrshire. The largest decrease is in Ceredigion, where the population is 3.2% smaller than in mid-2014, with a fall from 75,100 people to 72,700 living in the area.

Figure 2: The population growth rate differs at a local authority level

Population growth by local area, mid-2014 to mid-2019, local authorities in the UK

Families and households

In this section, the following definitions are used:

• a family is a married, civil partnered or cohabiting couple with or without children, or a lone parent with at least one child, who live at the same address; children may be dependent or non-dependent²

• a household is one person living alone, or a group of people (not necessarily related) living at the same address who share cooking facilities and share a living room, sitting room or dining area; a household can consist of a single family, more than one family, or no families in the case of a group of unrelated people

In 2019, the number of households in the UK was 27.8 million, representing an increase of 6.8% from 2009 (26 million).

The number of families living in the UK also saw an increase of 6.8% over the decade, increasing from 17.9 million in 2009 to 19.2 million in 2019. Altogether there were:

• 12.8 million married couple or civil partnership families (67%)

• 3.5 million cohabiting couple families (18%)

• 2.9 million lone parent families (15%)

Cohabiting couple families are the fastest-growing family type; since 2009, there have been an additional 772,000 cohabiting couple families (a growth rate of 28.1% over this period).

More young adults are living with their parents. In 2019, the first age at which more than 50% of young people left the parental home was 24 years. Two decades earlier, more than 50% of 21-year-olds had already left home. Young men aged 20 to 34 years living in the UK are more likely than young women to be living with their parents (32% and 21% respectively).

In addition, there have been increases in the numbers of people who are living alone – between 2009 and 2019, there has been a 9% increase (from 7.5 million to 8.2 million). This increase was driven primarily by the additional 401,000 older men living alone; a 31% increase for men aged 65 to 74 years and a 47% increase for men aged 75 years and over. In 2019, nearly half of those living alone (49.1%) were aged 65 years and over, and more than one out of every four (29%) were aged 75 years and over.

Notes for: The UK's population continues to grow, but at a slower rate than previously

1. Projections are based on the latest available mid-year population estimates for each UK country and the latest available births, deaths and migration data. Assumptions used for the projections are based on past, observed, long-term demographic trends. Therefore, projections do not predict the possible effects of future events (e.g. the coronavirus (COVID-19) pandemic which occurred after publication of the most recent round of projections based on 2018 mid-year population data).

2. Families and household statistics explained provides further explanation of the families and households definitions that are used.

Change in population size at the UK-level has four components: births, deaths, immigration and emigration.

The difference between the number of births and deaths is referred to as "natural change". When natural change is positive, there have been more births than deaths in the considered timeframe. When it is negative, there have been more deaths than births.

The difference between the number of long-term immigrants (people moving into the UK for more than 12 months) and the number of long-term emigrants (people moving out of the UK for more than 12 months) is termed "net migration". Those moving for less than 12 months are not recorded in the mid-year population estimates but are estimated elsewhere¹.

Natural change

In 2019, the UK experienced a natural change of 109,973 with 712,680 live births and 604,707 deaths: the lowest level of natural change since 2003.

Analysis of the births data in England and Wales in 2019 shows that the number of live births has decreased by 2.5% since 2018. The average number of children per woman for England and Wales decreased from 1.70 in 2018 to 1.65 in 2019.

Analysis of deaths registered in England and Wales in 2019 shows the number of deaths registered in England and Wales has decreased by 2.0% since 2018. This decrease is also visible when taking into account population size and age structure.

The natural change data presented in Figure 3 are for calendar years and so differ from the natural change component of change for the population estimates, which are calculated for mid-years (reference date 30 June).

Fluctuations in natural change have historically mirrored fluctuations in births. For example, Figure 3's left-most peak in natural change corresponds to the 1960s baby boom, which subsided in the 1970s. The second upturn in natural change is an "echo effect" of the first, whereby baby boomers are having children of their own.

Births peaked again more recently in 2012, at 813,000. Since 2012, most years have seen a reduction in the number of births compared with the previous year. In 2019, there were around 100,000 fewer births than in 2012, a reduction of 12.3% and more than the mid-2019 population of Lincoln.

The long-term trend in the number of deaths is more stable than in the number of births. The total number of deaths peaked in 1976 at 681,000. Much of the gradual decline in the number of deaths from 1985 and 2011 has been driven by people living longer. Since 2011, as a larger number of people reach older ages there has consequently been a general increase in the number of deaths, thus contributing to the decline in natural change.

The breakdown of natural change for the UK's constituent countries for the calendar year ending December 2019 is as follows:

• England's natural change was 114,135 (with 610,505 births and 496,370 deaths)

• Wales's natural change was negative 3,479 (with 29,704 births and 33,183 deaths)²

• Scotland's natural change was negative 8,245 (with 49,863 births and 58,108 deaths)

• Northern Ireland's natural change was 6,689 (with 22,447 births and 15,758 deaths).

For a detailed data time series on each country, please see Births in England and Wales summary tables, Deaths registered in England and Wales, and Scotland's Vital Events Reference Tables 2019 and Northern Ireland's NISRA, Birth Statistics: 2019,and NISRA, Death Statistics: 2019.

The average number of children a woman has during her lifetime is declining

Total fertility rate (TFR) is the hypothetical average number of children per woman a group of women would have in their childbearing years if they were to experience the age-specific fertility rates of the year in question. TFR of about 2.1 children per woman is the number of children a woman would need to have to sustain current population levels (ignoring migration) – also known as the replacement fertility level.

Figure 4 displays how TFR has changed over time. The TFR hit an all-time low in 2001 for the UK with an average of 1.63 children per woman. Following this low, the TFR increased steadily during the first decade of the 21st century, reaching 1.91 in 2008 and staying on or above 1.90 for the next four years. In 2013, there was a substantial drop in UK TFR to 1.83. The TFR has since continued to decline – and in 2018, the average number of children per woman was 1.68.

Age-specific fertility rates show a decline in fertility rates at younger ages and rises at older ages. In 2018, the age-specific fertility rates for women aged under 30 years were at their lowest since 1938. Fertility rates for women in this age group have been decreasing each year since 2013.

Net migration

For the majority of the 20th century, natural change was the main driver of UK population growth, with net migration a secondary factor. In the 1990s, however, net migration increased in influence and has been the main source of growth since 1999.

The findings in this section are based on the long-term international migration estimates, where the International Passenger Survey (IPS) is the main data source. International migration estimates for April 2020 onwards will no longer be measured using the IPS, following the pausing of the IPS as a result of the coronavirus. For more recent analysis on international migration estimates, please see our article on what’s changed since the coronavirus pandemic.

International migration estimates for April 2020 onwards will no longer be measured using the IPS, following the pausing of the IPS as a result of the coronavirus (COVID-19).

Long-term international migration data for the year ending March 2020 show that migrants continued to add to the UK population. An estimated 313,000 more people moved to the UK with an intention to stay 12 months or more than left in the year ending March 2020 (net migration). This is lower than the previous peak level of 331,000 in the year ending March 2015, however, levels have remained broadly stable since the end of 2016. Over the year ending March 2020, 715,000 people moved to the UK (immigration) and 403,000 left the UK (emigration) (Figure 5).

Figure 5: Long-term immigration, emigration and net migration have remained broadly stable since the end of 2016

Long-term international migration, UK, year ending June 2010 to year ending March 2020

Since 2016, overall migration levels have remained broadly similar. However, since 2019, there has been a change in migration patterns, which has led to an increase in net migration. This change in patterns is different for EU and non-EU citizens. EU net migration has decreased since 2015, following a three-year period of increase. Non-EU net migration has increased over the last year, following a gradual increase since 2013.

Decisions to migrate are complex and a person's decision to move to or from the UK will always be influenced by a range of social and economic factors.

The latest data on the population of the UK by country of birth and nationality is available in a separate bulletin and covers the period July 2019 to June 2020.

Notes for: Migration to the UK has been the main driver of population growth since the 1990s

1. Full details of definitions can be found in International Migration terms, definitions and frequently asked questions.

2. In 2019 there were an additional 161 births to women whose usual residence was outside England and Wales but were registered in England or Wales. There were also 1,288 deaths registered regarding people whose usual residence was outside England and Wales in 2019.

Like many other countries, the UK's age structure is shifting towards older ages. By 2050, it is projected that one in four people in the UK will be aged 65 years and over -- an increase from approximately one in five in 2019. This is the result of the combination of declining fertility rates and people living longer. While living longer may be a cause for celebration, the ageing population has implications on several policy areas.

The population aged 65 years and over is growing faster than other age groups

The UK's age structure is mainly determined by trends in fertility and mortality. Generally, both fertility and mortality rates have been declining in the UK. With fewer births and later deaths the overall age structure has become gradually older. 

According to the principal population projection, the population share of later-life age groups is set to increase further in future years. By 2041, the 1960s baby boomers will have aged into their 70s and 80s, and by 2069 there are projected to be an additional 7.5 million people aged 65 years and over in the UK, compared with 2019 figures. This would take the UK's 65 years and over age group to 19.8 million people, accounting for 26.2% of the projected population.

In 1999, around one in six people were 65 years and over (15.8%), this increased to one in every five people in 2019 (18.5%) and is projected to reach around one in every four people (23.9%) by 2039.

Comparatively, an estimated 20.4% of the population were under 16 years old in 1999, decreasing to 19.0% in 2019 and this is projected to decline to 16.9% by 2039. In 1999, 63.8% of the population were aged 16 to 64 years old, down to 62.5% in 2019 and projected to decline to 59.2% in 2039.

Within the UK, the older population make up higher proportions of the populations of rural and coastal than urban areas. The following interactive, Figure 6, shows how age structure differs by local authority over time.

Figure 6: Coastal areas have a higher proportion of the population who are aged 65 years and over

Broad age group percentage of the UK population by local authority, 1999, 2009, 2019, 2029, 2039

Notes:

1. Data for 1999, 2009 and 2019 are based on population estimates, for 2029 and 2039 data are based on population projections.

2. For Northern Ireland's local authorities in 1999, the data used is for Northern Ireland as a country. This is because the data collected in 1999 is not comparable at a local authority level.

Download the data

Figure 7 provides an interactive tool that will show you how the age and sex structure of a population can vary across the UK’s local authorities and constituent countries.

Figure 7: The age and sex structure of a population varies by local area

Population pyramids for the UK, by sex and single year of age, explorable by local authority and constituent country, 1999, 2009, 2019, 2029, 2039

One traditional measure used to consider the impact of an ageing population is the old-age dependency ratio (OADR). This measures the number of people of pensionable age and over per 1,000 people aged 16 years to State Pension age (SPA) and takes into account future changes to SPA that are in current UK legislation.

In 1999, the OADR was 299 and remained around this level until 2007 when it started to rise, peaking at 312 in 2010. Increases to SPA, firstly for women from 2010 to equalise with men's SPA and then gradual increases for both sexes, led to a fall in the OADR back to 288 in 2019. However, despite future increases in SPA in current legislation, the OADR is projected to reach 360 by 2043.

Higher numbers of people aged 65 years and over are in work in 2019 than ever before. Our June 2019 analysis looks at an alternative measure to the OADR, the Active Depenceny Ratio (ADR), that takes economic activity levels by age into account. Using this alternative measure, the analysis found economic dependency had decreased since the 1990s, despite the population becoming older. While the main explanation is increases in economic activity at older ages, immigration of those of working age has also had some effect. The ADR is projected to increase over the next 40 years, suggesting increased dependency, but more slowly than the OADR.

Improvements in life expectancy are slowing down

After decades of steady improvement in the UK's life expectancy, the latest figures from the National life tables show a continued slowdown in improvement of life expectancy in the UK. Life expectancy at birth improved slightly in 2017 to 2019, when compared with 2016 to 2018 life expectancy, and remained at 79.4 years for males and 83.1 years for females. These latest figures still show the highest life expectancy the UK has seen.

On average, females continue to live longer than males, however, the gap between the sexes has decreased over the last 30 years with males seeing greater improvements in life expectancy.

Within the UK, life expectancy at birth remained the same between 2016 to 2018 and 2017 to 2019 for females in Scotland and Wales and for males in Northern Ireland. Life expectancy at birth increased from 2016 to 2018 and 2017 to 2019 for females in Northern Ireland, males in Scotland and Wales and males and females in England.

In addition to the National life tables, we continue to monitor and report on the slowdown in life expectancy and mortality improvements in a number of publications. As we continue to see a slowdown in life expectancy improvements we will continue to analyse the data further to understand more about the causes behind this.