Demography and migration in Wales (Census 2021)
Unrounded population and household estimates, including an overview of the non-UK born population and characteristics of households and residents in Wales from the 2021 Census.
In this page
The Office for National Statistics (ONS) published Census 2021 rounded population and household estimates for local authorities in Wales (Office for National Statistics) on 28 June. We also published a statistical bulletin summarising the key points for Wales, looking at change over time and the composition of the population by sex and by five-year age groups for local authorities in Wales.
This update provides unrounded population and household estimates, including an overview of the non-UK born population and characteristics of households and residents in Wales. The ONS has also published Demography and migration: Census 2021 in England and Wales (Office for National Statistics) which includes some data down to output area.
- On Census Day, 21 March 2021, the size of the usual resident population in Wales was estimated to be 3,107,494, the largest population ever recorded through a census in Wales.
- There were 1,347,114 households with at least one usual resident in Wales on Census Day.
- In Wales, Poland remained the most common country of birth outside the UK in 2021 (24,832 people, 0.8% of all usual residents).
- The number of residents in Wales listing Romania as their country of birth increased almost fivefold (469.9%) between 2011 and 2021, increasing by 7,025.
- 124,557 usual residents (4.0%) held a non-UK passport, with the most common non-UK passport held being Polish.
- Of the 3.1 million usual residents in Wales in 2021, 3,051,549 (98.2%) lived in households and 55,945 (1.8%) lived in communal establishments.
- Overall, 63.1% of households (850,096) were single family households, 31.9% (429,559) were one person households and 5.0% (67,459) were multiple family or other household types.
Unrounded population and household estimates
Unrounded population and household estimates have been updated on StatsWales. This includes a breakdown of the population by single year of age.
The usual resident population in Wales is estimated to have grown by approximately 44,000 (1.4%) to 3,107,494 between Census 2011 and Census 2021.
In 2021, the average (median) age in Wales was 42 years. This is higher than the average (median) age of 41 years in 2011. The average (median) age in England in 2021 was 40 years.
The local authorities with the highest average (median) age were Powys (50 years), Conwy and Monmouthshire (both 49 years). The local authorities with the lowest average (median) age were Cardiff (34 years) and Newport (38 years).
The census collects various pieces of information which provide detail on the characteristics of those who migrated to Wales, whether that was within the last decade or even longer ago.
Changes in the size of the population are caused by births, deaths, and internal and international migration. Using data on live births and deaths registrations shows how much of the population change that is attributable to natural causes, and how much that is attributable to migration.
There were more deaths than births in Wales between 2011 and 2021. The population growth since 2011 is therefore due to positive net migration into Wales (approximately 55,000 usual residents).
Country of birth
Since 1851, the census has been collecting information on where people are born. It is often the preferred measure when looking at long-term changes in migration (Office for National Statistics) as a person’s place of birth does not change.
Out of the estimated 3.1 million usual residents in Wales in 2021, 2.9 million (93.1%) were born in the UK and 215,000 (6.9%) were born outside the UK. The number of residents in Wales born outside the UK has increased by 28.3% (48,000) between Census 2011 and Census 2021. In England, the number of residents born outside the UK has increased by 33.6% (2.5 million).
Figure 1: Top 10 non-UK countries of birth, 2011 and 2021
In Wales, Poland remained the most common country of birth outside the UK in 2021 (24,832 people, 0.8% of all usual residents). The largest percentage change since 2011 was for those who listed Romania as their country of birth. The number of residents in Wales listing Romania as their country of birth increased almost fivefold (469.9%) between 2011 and 2021, increasing by 7,025. This increase is mainly driven by working restrictions for Romanian citizens being lifted in 2014. The number listing the Republic of Ireland as their country of birth decreased by 2,177.
The percentage of usual residents born outside of Wales has increased from 27.3% (837,000) in 2011 to 29.1% (905,000) in 2021, including an increase of 23,000 people born in England.
Source: Census 2021
How country of birth varies across Wales
In Wales, 6.9% of usual residents were estimated to be born outside the UK. This ranged between 2.9% in Caerphilly to 16.5% in Cardiff.
Figure 2: Percentage of residents born outside the UK by local authority, 2021
The Isle of Anglesey is the only local authority in Wales where the number (112) and percentage of people born outside the UK has decreased (by 4.9%) since Census 2011. Newport and Flintshire had the largest increases in non-UK born residents, increasing by 57.5% and 55.7% respectively.
Source: Census 2021
Passports held by residents in Wales
In 2011, the census started collecting information on passport(s) held by usual residents, which is another measure that can be used to describe migration statistics (Office for National Statistics). It is often used as a proxy for nationality and a way of identifying those who hold dual or multiple nationalities.
Results from the 2021 Census estimate that 2.5 million usual residents in Wales (81.2%) held at least one passport and 583,000 (18.8%) did not have a passport. In England, 13.2% did not have a passport. The number of residents in Wales who did not have a passport decreased by 104,000 between Census 2011 and Census 2021.
In total, an estimated 2.4 million usual residents in Wales (77.2%) held a UK passport. The number of usual residents who held a non-UK passport was 125,000 (4.0%). Of these, 83,000 were EU passports, which is an increase from 51,000 in 2011 (an increase of 63.0%). The other 41,500 non-UK passports were from outside the EU (down 3.5% from 43,000 in 2011).
Figure 3: Top 10 non-UK passports held, 2011 and 2021
The number of Polish passports held in Wales in 2021 (26,000) was more than double the number of the next highest non-UK passport held, which was Irish at 10,000. The number of Polish passports held in Wales increased by 9,000 from 17,000 between Census 2011 and Census 2021. The number of Romanian passports held in Wales increased by 7,000 (from 1,000 to 8,000), overtaking India to become the third most common non-UK passport in Wales, after Poland and the Republic of Ireland.
The majority (8 out of the top 10) of the top non-UK passports held in Wales are European, whereas the majority of the top non-UK countries of birth are not European (6 out of 10). This is because people living in Wales with a non-European country of birth are less likely to hold a passport from their country of birth than people with a European country of birth.
Source: Census 2021
Address one year before the census
The Census asked respondents whether their address was the same as one year previously (that is, on 21 March 2020). These data can then be used to explore migration to Wales in the year before the Census.
In 2021, an estimated 16,000 Welsh residents (0.5% of the population) said that their address one year before the Census was outside the UK. This is a decrease compared with 2011, when 20,000 (0.7%) said that their address one year before the census was outside the UK.
A decline in the number of arrivals in the previous year had been expected, as a result of the coronavirus (COVID-19) pandemic. UK travel restrictions were enforced from March 2020 onwards and restrictions were also put in place in other countries across the world. As a result, migration to and from the UK in the year before the Census was highly restricted.
In Wales, Cardiff was the local authority with the highest percentage of the population with an address outside the UK one year before the Census 2021 (1.4%). Caerphilly had the lowest percentage (0.1%).
Age and year of arrival
Usual residents born outside the UK were asked when they most recently arrived to live in the UK. Combining this with their date of birth also provides information on their age of arrival.
Of the 215,000 residents in Wales in 2021 who were not born in the UK:
- 91,000 (42.1%) had arrived since 2011
- 62,000 (28.9%) had arrived between 2001 and 2010
- 63,000 (29.0%) had arrived before 2001
Figure 4: Non-UK born residents by year of arrival, 2021
Most non-UK born Welsh residents were under 30 when they arrived in the UK. The data on age of arrival show that:
- 35.0% non-UK-born Welsh residents (75,000) were below the age of 18 years when they arrived in the UK
- 38.9% (84,000) were aged 18 to 29 years
- 20.2% (43,000) were aged 30 to 44 years
- 5.2% (11,000) were aged 45 to 64 years
- 0.7% (2,000) were aged 65 years or older when they arrived in the UK
Source: Census 2021
The ONS has also published data about the short-term resident population for Wales and England from Census 2021 (Office for National Statistics), which includes people who had arrived in the UK within the year before Census Day and did not intend to stay longer than 12 months.
Household and resident characteristics
Census 2021 data on household and resident characteristics in Wales include data on household size, household composition, and deprivation status, as well as people’s marital and civil partnership status.
There were an estimated 1,347,114 households with at least one usual resident in Wales on 21 March 2021, an increase of around 44,438 (3.4%) since 2011. There were 3,051,549 usual residents (98.2%) living in a household. The remaining 55,945 usual residents (1.8%) lived in communal establishments. Communal establishments include residential care homes, university halls of residence, boarding schools, and prisons.
In Wales, 35.1% of households contained two people, with the majority of households (67.0%) containing one or two people. This is slightly higher than in 2011 when 65.6% of households contained one or two people.
This varied across local authorities in 2021, with 71.4% of households in Ceredigion containing one or two people, while 63.1% of households in Newport contained one or two people.
Figure 5: Size of household, 2021
Average household size is the average number of persons per household. It is calculated by dividing the overall number of usual residents in households by the overall number of households. In 2021, this was 2.3 residents per household in Wales, which is the same as 2011.
The local authorities with the largest average household size were Cardiff and Newport (both 2.4 residents per household). The local authority with the smallest average household size was Conwy (2.2 residents per household).
Source: Census 2021
Figure 6: Average household size by local authority, 2021
Source: Census 2021
Responses to the census are used to calculate household composition, which refers to the relationship between household members. For example, a household may consist of a family, of unrelated adults living together, or it might just be one person living alone. A family might be a couple or a family, including lone-parent families and multigenerational households.
In 2021, 63.1% of households were single family households, 31.9% were one person households and 5.0% were other household types, including households where multiple families lived together and households where unrelated adults lived together. This is similar to 2011, when 63.5% were single family households, 30.8% were one person households and 5.8% were other household types.
The most common types of single family households included those with a married or civil partnership couple with dependent children (11.9%), and those with a married or civil partnership with no children (10.8%). The greatest increase was for single family households with a cohabiting couple with non-dependent children, a household type that increased by 60.5% between 2011 and 2021 (from 6,613 in 2011 to 10,615 in 2021).
There were 196,056 one person households with residents aged 66 years or over (14.6% of all households). The remaining 233,503 (17.3%) one person households in 2021 were younger people.
In 2021, for other household types, there were 42,381 (3.1% of all households) in which members were full-time students or all aged 66 and above. There were 26,078 households (1.9%) in which multiple families lived together with dependent children.
Households in Wales and England were classified in terms of dimensions of deprivation, based on selected household characteristics. Specifically, households were considered to be deprived if they met one or more of the following four dimensions of deprivation:
- employment: where any member of a household, who is not a full-time student, is either unemployed or long-term sick
- education: no person in the household has at least five or more GCSE passes (grade A* to C or grade 4 and above) or equivalent qualifications, and no person aged 16 to 18 years is a full-time student
- health and disability: any person in the household has general health that is “bad” or “very bad” or has a long-term health problem
- housing: the household’s accommodation is either overcrowded, with an occupancy rating of negative 1 or less (implying that it has one fewer room or bedroom required for the number of occupants), or is in a shared dwelling, or has no central heating
Overall, 54.1% of households in Wales in 2021 were deprived in at least one of these dimensions, compared with 51.6% in England. The number of households in Wales deprived in at least one dimension has decreased since 2011, when 61.0% of households were deprived in at least one dimension.
In 2021, 33.4% households in Wales were deprived in only one dimension, 16.0% were deprived in two dimensions, 4.5% were deprived in three dimensions and 0.2% were deprived in all four dimensions. The remaining 45.9% were not deprived in any dimension.
The local authorities with the highest proportion of households deprived in at least one dimension were Blaenau Gwent (61.7%) and Merthyr Tydfil (59.8%).
The local authorities with the highest proportion of households not deprived in any dimension were Monmouthshire (51.7%) and the Vale of Glamorgan (51.0%).
Figure 7: Households deprived in a least one dimension, 2011 and 2021
Household deprivation is a complex topic, and the data here simply show how many households were deprived in any of the four stated dimensions available from the census. This repeats an equivalent release from the 2011 Census. Detailed information on the stated dimensions will be published in upcoming ONS topic releases and with the release of multivariate data.
Source: Census 2021
Another measure of deprivation at the household level in Wales is the Welsh Index of Multiple Deprivation (WIMD) which is the Welsh Government’s official measure of relative deprivation for small areas in Wales.
Legal partnership status
Same-sex marriage was legalised in 2014 and opposite-sex civil partnerships were legalised in 2019. The questions on marriage and civil partnerships were updated for 2021 to reflect this.
In Wales, 43.8% of all usual residents aged 16 or older were married or in a civil partnership. This was the largest group in 2021. However, this has decreased since 2011, when 46.7% were married or in a civil partnership.
The percentage of people who have never married or registered a civil partnership increased by 3.7 percentage points, from 33.5% in 2011 to 37.2% in 2021. The number of people who were divorced or whose civil partnership had been dissolved rose slightly, from 9.7% in 2011 to 9.9% in 2021.
Figure 8: Legal partnership status, usual residents aged 16 or older, 2011 and 2021
Source: Census 2021
Quality and methodology information
For full quality and methodology information, including a glossary of terms, please visit the ONS’ quality and methodology information report.
Population change in certain areas may reflect how the coronavirus (COVID-19) pandemic affected people’s choice of usual residence on Census Day. These changes might have been temporary for some and more long-lasting for others.
There will be further releases of Census 2021 data from November, including information about topics such as the Welsh language. For further information about the data and analysis that will be available, see the ONS’ release plans.
Reports comparing the Census 2021 population estimates with the latest mid-year estimates (Office for National Statistics) and the ONS’ admin-based population estimates, including explanations for any differences, are planned for publication later this year by the ONS.
The census collects data on the country of birth, passport(s) held, and address one year ago of all census residents. Those who were born outside the UK are also asked to provide the date at which they arrived in the UK, which can be combined with birthdate data to show their age at arrival. Finally, the census also collects data on the size and characteristics of the short-term resident population, who arrived in the year prior to census but did not intend to be in the country for more than 12 months.
People can hold multiple passports. Double-counting residents is prevented by including them in only one passport category. When a person had more than one passport, they were categorised in the following priority order:
- UK passport
- Irish passport
- Other country passport
For a full glossary of terms, please see the ONS’ Census 2021 dictionary.
Average (median) age
The age of the person in the middle of the group, such that one half of the group is younger than that person and the other half is older. Age refers to age at last birthday rather than the exact age.
National Statistics status
The United Kingdom Statistics Authority has designated these statistics as National Statistics, in accordance with the Statistics and Registration Service Act 2007 and signifying compliance with the Code of Practice for Statistics.
National Statistics status means that official statistics meet the highest standards of trustworthiness, quality, and public value.
All official statistics should comply with all aspects of the Code of Practice for Statistics. They are awarded National Statistics status following an assessment by the UK Statistics Authority’s regulatory arm. The Authority considers whether the statistics meet the highest standards of Code compliance, including the value they add to public decisions and debate.
It is Welsh Government’s responsibility to maintain compliance with the standards expected of National Statistics. If we become concerned about whether these statistics are still meeting the appropriate standards, we will discuss any concerns with the Authority promptly. National Statistics status can be removed at any point when the highest standards are not maintained, and reinstated when standards are restored.
The designation of these statistics as National Statistics was confirmed to the ONS in June 2022 following a full assessment against the Code of Practice by the Office for Statistics Regulation.
Well-being of Future Generations Act (WFG)
The Well-being of Future Generations Act 2015 is about improving the social, economic, environmental, and cultural wellbeing of Wales. The Act puts in place seven wellbeing goals for Wales. These are for a more equal, prosperous, resilient, healthier, and globally responsible Wales, with cohesive communities and a vibrant culture and thriving Welsh language. Under section (10)(1) of the Act, the Welsh Ministers must (a) publish indicators (“national indicators”) that must be applied for the purpose of measuring progress towards the achievement of the wellbeing goals, and (b) lay a copy of the national indicators before Senedd Cymru. Under section 10(8) of the Well-being of Future Generations Act, where the Welsh Ministers revise the national indicators, they must as soon as reasonably practicable (a) publish the indicators as revised and (b) lay a copy of them before the Senedd. These national indicators were laid before the Senedd in 2021. The indicators laid on 14 December 2021 replace the set laid on 16 March 2016.
Information on the indicators, along with narratives for each of the wellbeing goals and associated technical information is available in the Wellbeing of Wales report.
Further information on the Well-being of Future Generations (Wales) Act 2015.
The statistics included in this release could also provide supporting narrative to the national indicators and be used by public services boards in relation to their local wellbeing assessments and local wellbeing plans.