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Census 2021

Demography and migration in Wales: Census 2021

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.

On 2 November, the ONS published an update providing 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. The Welsh Government also published a statistical bulletin summarising the key results for Wales. Some data will be made available on StatsWales in the coming weeks.

Main points

Unrounded population estimates

  • 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 an estimated 1,347,114 households with at least one usual resident in Wales on Census Day.
  • 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.


  • 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).
  • 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.
  • 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.
  • 124,557 usual residents (4.0%) held a non-UK passport, with the most common non-UK passport held being Polish.

Household characteristics

  • 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.
  • 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.
  • 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.
  • 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%).
  • 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 percent 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.

UK armed forces veterans in Wales: Census 2021

On 10 November, the Office for National Statistics (ONS) has published UK armed forces veterans, England and Wales: Census 2021 (Office for National Statistics). The Welsh Government also published a statistical bulletin summarising the key results for Wales.

Main points

  • In 2021, around 115,000 people in Wales reported that they had previously served in the UK armed forces. This is around 4.5% of usual residents aged 16 years or older.
  • The percentage of UK armed forces veterans was higher in Wales than it was in England (3.8%, 1.7 million).
  • Of the UK armed forces veteran population in Wales, 76.3% (88,000 people) previously served in the regular forces, 19.3% (22,000 people) previously served in the reserve forces, and 4.5% (5,000 people) served in both the regular and reserve forces.
  • Around 2,000 UK armed forces veterans (1.8%) lived in communal establishments and the remainder (around 113,000, 98.2%) lived in households.
  • The percentage of households with one or more persons who had served in the UK armed forces was higher in Wales (8.1%, 109,000) than it was in England (7.0%, 1.6 million).
  • Across Wales, the local authorities with the highest proportion of veterans include Conwy (5.9%, 6,000 people), Pembrokeshire (5.7%, 6,000 people) and the Isle of Anglesey (5.6%, 3,000 people).

ONS’ Census 2021 release plans

The ONS aims to publish all main 2021 Census data on the population of Wales and England within two years of the census. These publications will be released in three phases:

  • Phase 1 started with the rounded population and household estimates, and will also include topic summaries and area profiles published from autumn 2022. The topic summaries (in order of when they are likely to be published) are:
  • Phase 2 is from early 2023. It will include the publication of statistical commentaries alongside topic summary data, multivariate data for the usual resident population base and the release of data on the short-term resident population.
  • Phase 3 will begin in spring 2023. This phase will include data for alternative population bases, small populations, detailed migration data, ‘flow’ data and microdata samples.

For more information, please see the ONS release plans.

Using Census 2021 data to measure the non-UK population (non-UK born and non-British nationals) 

As part of the transformations of population and migration statistics (Office for National Statistics) and the Labour Force Survey (LFS) (Office for National Statistics), ONS are reviewing the best methods to produce estimates of the UK population. Therefore, the population of the UK by country of birth and nationality series (Office for National Statistics) using the APS will be discontinued. ONS are exploring provisional measures that can roll forward census data to produce a more up-to-date picture. An example will be provided in the long-term international migration release on 24 November 2022. ONS published a statement providing more information.

Welsh language statistics

For information on Welsh language statistics, please see the Statistics Wales quarterly update.


Martin Parry

Telephone: 0300 025 0373



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