The usual resident population in Wales was 3,107,500 on Census Day, 21 March 2021.

This was the largest population ever recorded through a census in Wales – an increase of 44,000 (1.4%) compared with Census Day 2011.

However, 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.

Newport was the fastest growing local authority in Wales since 2011 at 9.5%. 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%).

Commenting on today’s census figures for Wales, Office for National Statistics director Jen Woolford said: “Today’s census statistics begin to paint a rich and detailed snapshot of the nation and how we were living during the pandemic. They show that while the overall population of Wales continued to grow across the decade, that was not the case across every local authority in the country.

“For example, rural and/or coastal regions such as Ceredigion, Blaenau Gwent and Gwynedd have all seen their population decline since the last census. Rural areas also tended to have older populations and lower population density, particularly Powys. The youngest and most densely populated parts of Wales are all urban areas of the south, such as Cardiff and Newport.

“Ultimately, the full suite of census results, based on the information we all gave, will ensure decisions about how the billions of pounds we spend each year as a nation are made using the best possible evidence. This includes planning our emergency services, mental health care, school places, hospital beds, houses, roads, buses, trains, trams, GPs and dentists’ services.”

Jen added: “Since census day the world has continued to change. People continue to move home, some people will have left the country, others will have arrived. People will have changed jobs, some of us now work in offices once again, while others continue to work from home.

“We need to understand all of this and more. The results from Census 2021 – and there’s lots more to follow - therefore provide a key bridge from the past to the future as we deliver more frequent, relevant and timely statistics using data from across government to allow us to understand population change in local areas this year and beyond.”

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 (58,800).

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 our interactive article, How the population changed where you live: Census 2021.

Other important findings:

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

  • The population of Wales is ageing with 21.3% of people aged 65 years and over, up from 18.4% a decade ago.

  • There were 1,347,100 households in Wales on Census Day - this is an increase of 44,400 (3.4%) since 2011, when there were 1,302,676 households.

  • 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.

These population and household population figures are the first in a series of Census 2021 data being released over the next two years. From October, until the end of the year, initial topic summary reports including demography, Welsh language, migration, ethnicity, religion, UK armed forces veterans, education, health, the labour market, sexual orientation and gender identity will be released. More information can be found in our Census 2021 release plans.

Note to editors:

  • In July, we will explain how we are transforming our population and migration statistics beyond a traditional census. We will publish a proof of concept for producing “admin-based” population estimates using information from health, tax, benefits and education data sources, among others. We will also publish a statistical design for admin-based migration estimates.