How many people live in Wales?

Published 30/06/2022   |   Last Updated 01/07/2022   |   Reading Time minutes

The first results from the 2021 Census were published on 28 June. They show the usual resident population of Wales on 21 March 2021 was estimated to be 3,107,500. This is an increase of 44,000 (1.4%) since the 2011 Census. More detailed information including data on Welsh language, sexual orientation and gender identity will be published later this year. What we don’t know is how holding the Census during the pandemic may have impacted on people’s choice of a usual address.

What do the first results from the 2021 Census show?

The Office for National Statistics (ONS) published the first results from the 2021 Census in the statistical bulletin Population and household estimates, Wales: Census 2021. This release includes rounded population and household estimates for local authorities in Wales, by sex and five-year age groups. The headline results for Wales show:

  • The usual resident population in Wales on Census Day, 21 March 2021, was 3,107,500; the largest population recorded by a census in Wales;
  • This is a population increase of 44,000 (1.4%) since the 2011 Census when the population was 3,063,456;
  • In 2021 there were 1,586,600 women (51.1%) and 1,521,000 (48.9%) men;
  • The proportion of the population aged 65 years and over increased from 18.4% in 2011 to 21.3% in 2021;
  • On average there were 150 residents per square kilometre in 2021 compared to 434 per square kilometre in England; and
  • There were 1,347,100 households with at least one usual resident, this is an increase of 44,400 (3.4%) since 2011.

Population growth

Between 2011 and 2021 the rate of population growth in Wales (1.4%) was lower than England (6.6%) and all the English regions. The East of England was the English region with the highest population change (8.3%) and the North East the lowest (1.9%).

The rate of population growth slowed in Wales between 2011 and 2021 (1.4%) compared to 2001 and 2011, when the population grew by 5.5%.

Figure 1: Population 1801 to 2021, Wales

Source: Office for National Statistics, Population and household estimates, Wales: Census 2021

ONS explains that between April 2011 and March 2021 there were more deaths registered in Wales (332,000) than live births (321,000), representing a natural decrease of around 11,000 usual residents. With the population growth since 2011 due to net positive migration of around 55,000 usual residents.

Local authority population change

Newport (9.5%) had the highest population growth since 2011, followed by Cardiff (4.7%) and Bridgend (4.5%). Seven local authorities experienced population decreases, the largest were Ceredigion (5.8%), Blaenau Gwent (4.2%) and Gwynedd (3.7%). The ONS has produced a useful interactive tool that allows you to explore how populations have changed in local authorities across England and Wales.

Cardiff was the most densely populated local authority in Wales with 2,572 residents per square kilometre whereas Powys was the least densely populated with 26 residents per kilometre.

ONS explains that:

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.

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


Source: Office for National Statistics, Population and household estimates, Wales: Census 2021

An ageing population

The number of people in older age groups continues to increase. In 2011, 18.4% (562,544) of the population were aged 65 years or older. In 2021 this had increased to 21.3% (662,000). This compares to 18.4% of the population in England who are aged 65 and over.

The percentage of people aged 90 and over also increased in Wales from 0.8% (25,200) in 2011 to 1.0% in 2021 (29,700). This compares to 0.9% in England in 2021.

The ONS has published a comparison of the numbers of people by age and sex between the 2011 and 2021 censuses. In their glossary on the census results ONS defines sex as:

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

A topic summary on gender identity is expected to be published later in the year.

Figure 3: Age and sex of the population, 2011 to 2021, Wales

Source: Office for National Statistics, Population and household estimates, Wales: Census 2021

What do the Census results mean for the mid-year population estimates?

The latest mid-year population estimates produced by the ONS are based on the 2011 Census and adjusted for live births, deaths and migration. The further we move away from the previous census the more uncertain these estimates become. Hence the 2021 Census is important for understanding the accuracy of other population estimates and getting a more up to date picture of the population of Wales. ONS is planning on publishing reports comparing the 2021 Census with the latest mid-year estimates and their admin-based population estimates later this year.

How many people responded to the 2021 Census?

The ONS states that the person response rate for the 2021 Census in Wales was 96.4% of the usual resident population with the proportion of returns submitted online in Wales (68%) being lower than England (90%). ONS indicates that the lower proportion of online returns in Wales is likely due to a higher percentage of households in which initial contact was with a paper questionnaire rather than an online access code.

When will census data be published for Northern Ireland and Scotland?

The Census in Northern Ireland was conducted on 21 March 2021 and the first results have been published by the Northern Ireland Statistics and Research Agency. Scotland’s census was moved to 20 March 2022 and the results will be published from 2023 onwards.

When will more detailed 2021 Census data be published?

Unrounded population and household estimates are due to be published from October along with topic summaries including Welsh language, sexual orientation, gender identity and veterans of the UK armed forces. More details are available in ONS’ release plans.

Article by Helen Jones, Senedd Research, Welsh Parliament