Population and household estimates, Wales: Census 2021

This page is also available in Welsh (Cymraeg).

• On Census Day, 21 March 2021, the size of the usual resident population in Wales was 3,107,500; this was the largest population ever recorded through a census in Wales.

• The population of Wales has grown by 44,000 (1.4%) since the last census in 2011, when it was 3,063,456.

• There were 1,586,600 women (51.1% of the population) and 1,521,000 men (48.9%) in Wales.

• There were more people than ever before in the older age groups; the proportion of the population who were aged 65 years and over was 21.3% (up from 18.4% in 2011).

• There were 1,347,100 households with at least one usual resident in Wales on Census Day; this is an increase of 44,400 (3.4%) since 2011, when there were 1,302,676 households.

The usual resident population of Wales was 3,107,500 in 2021 (5.2% of the total population of England and Wales).

This was the largest population ever recorded through a census in Wales. The population increased by 44,000 (1.4%) compared with Census Day 2011, when there were 3,063,456 people in Wales.

The rate of population growth in Wales was considerably lower than in England, where the population grew by 6.6%. Population growth was also lower in Wales than in all English regions. The rate of growth in Wales was nearly six times lower than the East of England, the English region with the highest percentage change in the size of the population (8.3%). It was also lower than the English region with the lowest population growth, the North East (1.9%).

The rate of population growth in Wales across the last decade (1.4%) is lower than the rate between 2001 and 2011, when the population grew by 5.5%. In England, the rate of population growth also slowed but to a lesser extent (from 7.9% between 2001 and 2011, to 6.6% between 2011 and 2021).

Since the first census of Great Britain in 1801, the rate of population growth in Wales was highest between 1801 and 1921. During this period, the population grew by more than 13% per decade on average. The population then declined by 2.4% between 1921 and 1931 and had only increased by a small amount (0.2%) when the next census was taken in 1951. The population has continued to grow in each 10-year period after this, but at a much slower rate (between 0.7% and 5.5% in each decade).

Figure 1: The population continues to increase in Wales

Population 1801 to 2021, Wales

Notes:

1. There was no census in 1941, because of the Second World War.

2. Censuses before 1981 recorded population present, rather than usual residents.

3. From 1981, statistics relate to usual residents, which from 2001 onwards include estimates of those not counted.

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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, as well as migration estimates, can provide a more detailed understanding of the components of population change since 2011. These may not align perfectly with census estimates for a number of reasons - see the Strengths and limitations section for further information.

Monthly data show that from April 2011 until the end of March 2021 there were 321,000 live births and 332,000 deaths registered in Wales. This represents a natural decrease of approximately 11,000 usual residents. The population growth since 2011 is because of positive net migration (approximately 55,000 usual residents) into Wales.

The local authority with the largest population in 2021 was Cardiff, which had 362,400 usual residents. The local authority with the smallest population was Merthyr Tydfil, which had 58,800 usual residents.

Newport saw the highest rate of population growth since 2011 (at 9.5%). This is higher than the population growth rates for both Wales (1.4%) and England (6.6%). The next highest rate of population growth was in Cardiff (4.7%), followed by Bridgend (4.5%).

Several local authorities had lower populations in 2021 than in 2011. The greatest rates of population decline since 2011 were in Ceredigion (5.8%), Blaenau Gwent (4.2%) and Gwynedd (3.7%).

You can find out more about how the population has changed in different local authority areas and how they compare with others across England and Wales in How the population changed where you live: Census 2021.

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.

Every census has unique circumstances, and for Census 2021 the data will be particularly important for understanding the population and its characteristics during the coronavirus pandemic. Our Quality and methodology information (QMI) for Census 2021 report explains what this means for the data. We have already been able to use early census data to inform our response to the coronavirus pandemic and to support our humanitarian response to the Russian invasion of Ukraine.

Figure 2: Population change between 2011 and 2021, local authorities in Wales

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Overall, there were 1,586,600 women (51.1% of the overall population) and 1,521,000 men (48.9%) in Wales in 2021. This is very similar to the ratio between women (51.0%) and men (49.0%) in England. It is also similar to the ratio in Wales from 2011, when 50.9% (1,559,228) of the population were female and 49.1% (1,504,228) were male. 

The trend of population ageing has continued, with more people than ever before in the older age groups. Over one-fifth (21.3%) of the Welsh population in 2021 (662,000) were aged 65 years and over, up from 18.4% (562,544) in 2011. The size of the population aged 90 years and over (29,700, 1.0%) has increased since 2011, when 25,200, 0.8%, were aged 90 years and over.

The same patterns were seen in England, where the percentage of the population aged 65 years and over rose from 16.3% in 2011 to 18.4% in 2021. The percentage aged 90 years and over also increased from 0.8% in 2011 to 0.9% in 2021.

Nearly two-thirds (62.2%) of the Welsh population (1,931,800) were aged 15 to 64 years. The size of this age group has declined slightly since 2011, when 64.7% of the overall population (1,981,784) were aged 15 to 64 years.

The remaining 16.5% of the population (513,800) in Wales were aged under 15 years. The size of this age group has also decreased since 2011, when 16.9% (519,128) were aged under 15 years.

Figure 3: The trend for population ageing has continued

Age and sex of the population, 2011 to 2021, Wales

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Wales had a larger percentage of the population aged 65 years and over than all English regions except the South West, where 22.3% of the population were in this age group. The areas of Wales with the highest percentages of people aged 65 years and over were Powys (27.8%), Conwy (27.4%) and the Isle of Anglesey (26.4%), and the area with the highest percentage of people aged 90 years and over was Conwy (1.5%).

The percentage of the population aged 15 to 64 years was larger in England (64.2%) than in Wales (62.2%). The only English region with a lower percentage of people in this age group than Wales was the South West (61.8%). The areas of Wales with the highest percentages of people aged 15 to 64 years were Cardiff (68.4%) and Newport (64.2%).

Finally, the percentage of the population aged below 15 years was also larger in England (17.4%) than in Wales (16.5%). Once more, the South West (15.9%) was the only English region with a lower percentage of people in this age group than Wales. The Welsh local authorities with the highest percentages of the population aged under 15 years were Newport (19.0%) and Merthyr Tydfil (18.0%), whereas Ceredigion (13.1%) and Powys (14.4%) had the lowest.

Figure 4: Age structure of the population, 2021, local authorities in Wales

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There were 150 residents per square kilometre in Wales in 2021. This is about the same as 1.1 residents per football pitch-sized area of land. It is slightly higher than the 148 residents per square kilometre in 2011 and compares with 106 residents per square kilometre a century ago in 1921.

The population density in Wales is considerably lower than the population density in England, where there were 434 residents per square kilometre. Wales also had a lower population density than the least densely populated region of England, the South West (239 residents per square kilometre). London, which is the most densely populated English region (5,598 residents per square kilometre), was more than 37 times more densely populated than Wales.

The most densely populated local authority in Wales was Cardiff (2,572 residents per square kilometre), which was more than three times as densely populated as the next highest area, Newport (838 residents per square kilometre). The least densely populated local authority was Powys (26 residents per square kilometre). Other areas with low population density included Ceredigion (40 residents per square kilometre) and Gwynedd (46 residents per square kilometre).

Figure 5: Population density, 2021 and changes since 2011, local authorities in Wales

Notes:

1. Population density for 2021 has been calculated using population estimates rounded to the nearest hundred.

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The census also allows us to estimate the number of households in Wales. As per our Glossary definition, a household must have at least one usual resident.

There were 1,347,100 households in Wales on Census Day, which is a 3.4% increase (44,400 more households) on the 1,302,676 households in 2011. This is a lower rate of growth than between 2001 and 2011 in Wales, when the number of households grew by 7.7%.

The growth in the number of households in Wales was lower than in England, where there were 6.2% more households compared with 2011. The rate of increase in Wales was also lower than every region in England, which ranged from 4.1% in the North East to 8.5% in the East of England.

All but three local authorities in Wales saw an increase in the number of households compared with 2011. The local authorities that saw the highest increases were Newport (8.1% increase), the Vale of Glamorgan (7.5% increase) and Monmouthshire (7.0% increase). The areas where there were decreases in the number of households were Gwynedd (2.6% decrease), Ceredigion (2.1% decrease) and Blaenau Gwent (0.4% decrease).

Figure 6: Changes in the number of households between 2011 and 2021, local authorities in Wales

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This bulletin has reported rounded population and household estimates for local authorities in Wales. We have also published a bulletin for rounded population and household estimates in both England and Wales.

Unrounded population and household estimates are due to be published in autumn 2022. This will also include a breakdown of the population by single year of age, rather than broad age groups.

Read about other data and analysis that will be available from Census 2021 in our release plans.

Age

A person's age on Census Day, 21 March 2021 in Wales. Infants aged under 1 year are classified as 0 years of age.

Household

A household is defined as:

• 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 or sitting room, or dining area

This includes:

• all sheltered accommodation units in an establishment (irrespective of whether there are other communal facilities), and

• all people living in caravans on any type of site that is their usual residence; this will include anyone who has no other usual residence elsewhere in the UK

A household must contain at least one person whose place of usual residence is at the address. A group of short-term residents living together is not classified as a household, and neither is a group of people at an address where only visitors are staying.

Local authority

The general term for a body administering local government services.

In Wales, there are single tier unitary authorities. In England, local government is administered by either single tier or two-tier local authorities. The single tier authorities comprise unitary authorities, metropolitan districts and London boroughs, though some services such as transport planning are carried out by the Greater London Authority. The two-tier authorities elsewhere comprise counties and non-metropolitan districts.

Population density

This is the number of people who live within an area per square kilometre. One square kilometre is equal to 100 hectares.

Sex

This is the sex recorded by the person completing the census. The options were "Female" and "Male".

Usual resident

A usual resident of Wales is anyone who was living or staying in Wales for 12 months or more on Census Day, 21 March 2021, or who had a permanent address in Wales and were staying outside Wales for less than 12 months.

Reference date

The census provides estimates of the characteristics of all people and households in England and Wales on Census Day, 21 March 2021. It is carried out every 10 years and gives us the most accurate estimate of all the people and households in England and Wales.

We are responsible for carrying out the census in England and Wales, but will also release outputs for the UK in partnership with the Welsh Government, the National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA). The census in Northern Ireland was also conducted on 21 March 2021, whereas Scotland's census was moved to 20 March 2022. All UK census offices are working closely together to understand how this difference in reference dates will impact UK-wide population and housing statistics, in terms of both timing and scope.

Response rate

The person response rate is the number of usual residents for whom individual details were provided on a returned questionnaire, divided by the estimated usual resident population.

The person response rate for Census 2021 in Wales was 96.4% of the usual resident population, and over 94% in all local authorities.

The proportion of returns submitted online was lower in Wales (68%) than in England (90%). This is likely because Wales had a higher percentage than England of households in which initial contact was with a paper questionnaire rather than an online access code (50% in Wales compared with 9% in England), as they were in areas where the take-up of the online option was expected to be low.

For England and Wales as a whole, the person response rate was 97% of the usual resident population and over 88% in all local authorities. This exceeded our target response rate of 94% overall and 80% in all local authorities.

Parliamentary requirements

This bulletin was shared with the relevant ministers in both the UK government and Welsh Government on Monday 27 June, to meet the requirements within Section 4 of the Census Act 1920 that census returns are to be printed and laid before Parliament. This was agreed by the National Statistician.

Strengths

The census provides the most detailed picture possible of the entire population, with the same core questions asked to everybody across England and Wales.

The Office for Statistics Regulation has independently assessed the census estimates and checked compliance with the Code of Practice for Statistics. The UK Statistics Authority assigned National Statistics designation to Census 2021 outputs, providing assurance that these statistics are of the highest quality and value to users.

We undertook a rigorous and comprehensive quality assurance process, including comparing against the widest range of alternative and complementary data sources ever. In addition, for the first time, we invited local authorities to review provisional census estimates, drawing upon their local expertise, in parallel to our own quality assurance checks. Detailed information is provided in our Maximising the quality of Census 2021 population estimates report.

Census estimates are important for understanding the accuracy of other population estimates. For example, mid-year population estimates (MYEs) are based on the most recent census and adjusted for live births, deaths and migration, but the potential for error in MYEs increases over time between censuses. We are also developing admin-based population estimates (ABPEs), which use administrative data sources rather than being based on census estimates. Reports comparing the Census 2021 population estimates with the latest MYEs and ABPEs, including explanations for any differences, are planned for publication later this year.

Our very high response rate and extensive online collection has ensured that we have collected extremely high-quality data about the population and its characteristics on Census Day. It was particularly important to understand how the coronavirus (COVID-19) pandemic affected, and continues to affect, our population in a variety of ways (for example, health impacts, working from home). Census data and our ongoing transformation of our social statistics system will help us to both understand and to measure population change more effectively than ever before.

Limitations and mitigations

The first results from Census 2021 provide early rounded population and household estimates for England and Wales. Because of this rounding, figures may not add exactly. Unrounded figures will be released in autumn 2022. Figures may differ slightly in future releases because of the impact of removing rounding and applying further statistical processes. Unrounded historical census data are used for all comparisons with previous censuses.

Census statistics are estimates rather than counts, and therefore have measures of uncertainty associated with them. We take numerous steps to minimise possible sources of error, as described in our Quality and Methodology Information (QMI) report.

The coronavirus (COVID-19) pandemic may have affected some people's choice of usual residence on Census Day, for example, students and in some urban areas. These changes might have been temporary for some and more long-lasting for others. We discuss what this means for the data in our QMI report.

No census is perfect - some people are inevitably missed or counted twice. Our Census Coverage Survey (CCS) enables us to estimate how many people have been missed or double-counted. We also have processes that check for and resolve multiple responses, allowing us to adjust the census counts accordingly. More information is provided in our Maximising the quality of Census 2021 population estimates report.

As with all self-completion questionnaires, some forms will have contained incorrect, incomplete, or missing information about a person or household. We used editing and imputation strategies to correct inconsistencies and missing information. Further information will be provided in a more detailed report later this year.

National Statistics status for Census 2021

These National Statistics have been independently assessed by the UK Statistics Authority. They have been produced by following the standards set out in the Code of Practice for Statistics and the Statistics and Registration Service Act 2007.

This means that they:

• meet identified user needs

• are well explained and easily accessible

• are produced based on appropriate data and methods

• are managed impartially and objectively in the public interest.

Date of most recent full assessment: June 2022