The UK population at mid-year 2021 was estimated to be 67.0 million, an increase of 3.7 million (5.9%) on the population in mid-2011.
- Over the 10 years between 2011 and 2021, the population of England increased by 6.5% to an estimated 56,536,000, the highest rate of the four countries of the UK; the estimated population of Northern Ireland increased by 5.0% to 1,905,000, Scotland by 3.4% to 5,480,000, and Wales by 1.4% to an estimated 3,105,000.
- The mid-2021 population estimates for England, Wales and Northern Ireland are based on the 2021 censuses for England, Wales, and Northern Ireland.
- For Scotland, the mid-2021 population estimates are rolled forward from mid-2020, as Scotland’s census was moved to 2022 because of the impact of the coronavirus (COVID-19) pandemic; this means that population estimates based on Scotland’s Census 2022 are not yet available.
2.The UK population at mid-2021
We estimate the UK population in mid-2021 to be 67.0 million (67,026,292). This is an aggregate of the estimates for the four constituent countries. For England, Wales, and Northern Ireland these are the first mid-year population estimates based on the 2021 censuses for these countries. For Scotland the mid-2021 population estimates were rolled forward from mid-2020 as the census in Scotland took place in March 2022, a year later than the rest of the UK, because of the impact of the coronavirus (COVID-19) pandemic.
The mid-2021 population estimates are primarily based on the 2021 censuses (for England and Wales, and Northern Ireland). The usual resident population as at Census day (21 March 2021), by single year of age, is aged on to 30 June 2021 and then births, deaths and migration are accounted for.
Censuses provide the most accurate estimate of the population and therefore the reliability of mid-year estimates is very high immediately following a census. The figures will be revised in the next two years to include updated estimates for Scotland, incorporating the 2022 Census for Scotland. We will also incorporate revisions to international migration data as we continue our transformation of population and migration statistics.
3.Population change for UK countries
Overall, England had the highest population density of the four countries of the UK at mid-2021. However, this includes a wide variation within England, where the population density in London was 5,596 people per square kilometre (km) and the South West was 240 people per square km.
The median age of the population in the UK was 40.7 years in mid-2021, a year higher than in mid-2011. The increase in median age over the decade was highest in Northern Ireland, though at 39.8 years, this was still the lowest of the countries in the UK. Wales had the highest median age at 43.1 years.
| Population mid-2011 | Population mid-2021 | Median age mid-2011 | Median age mid-2021 | Population density (pop per sq. km) mid-2021 | |
|---|---|---|---|---|---|
| UK | 63,285,000 | 67,026,000 | 39.6 | 40.7 | 276 |
| England | 53,107,000 | 56,536,000 | 39.4 | 40.5 | 434 |
| Wales | 3,064,000 | 3,105,000 | 41.5 | 43.1 | 150 |
| Northern Ireland | 1,814,000 | 1,905,000 | 37.4 | 39.8 | 141 |
| Scotland | 5,300,000 | 5,480,000 | 41.3 | 42.2 | 70 |
Figure 1 shows the percentage change in population of the UK during the fifty-year period from mid-1971 to mid-2021. The population of the UK increased by approximately 11.1 million (19.8%) during the last fifty years and by approximately 3.7 million (5.9%) during the last decade. Population growth in the latest decade was lower than the previous decade in all four UK countries.
Figure 1: Mid-year population change for the UK and its constituent countries, decennial intervals, mid-1971 to mid-2021
Source: Office for National Statistics, National Records of Scotland, Northern Ireland Statistics and Research Agency – Population estimates
Notes:
- Mid-2021 figures for Scotland are rolled forward from mid-2020, as its census was held in 2022.
4.Population of England and Wales
The mid-2021 population estimate for England and Wales was 59,642,000, with the population for England at 56,536,000 and Wales at 3,105,000. Census 2021 for England and Wales took place on 21 March 2021 and the mid-year population estimates for England and Wales are based on these with adjustments made for ageing, births, deaths and migration in the 101 days until 30 June 2021.
During the period between census day and mid-year 2021, most restrictions related to the coronavirus (COVID-19) pandemic were lifted. However, restrictions were lifted on different dates in England and Wales. Alongside the lifting of restrictions, COVID-19 vaccinations were made available to all adults. The rollout of vaccinations resulted in greater interaction between individuals and the administrative data that we use to measure internal migration (movement between one part of the UK and another). We have adjusted our methods to account for this by using Census 2021 data. Full details on this can be found in our Population estimates for the UK, mid-2021 methodology guide.
Components of change between census day and mid-year 2021 in England and Wales
The mid-2021 estimates are based on Census 2021 and produced using the following method:
- ageing on the estimates from Census 2021 for England and Wales, by single year of age and local authority
- adding the births in England and Wales for the period between Census 2021 and mid-year 2021 (171,000) and subtracting deaths (132,000)
- accounting for net international migration (1,000) and internal migration (5,000)
- no adjustments for either prisoners or home or foreign armed forces personnel have been made
Estimates of international migration into and out of the UK are experimental and provisional. They are based on administrative and survey data using a range of data sources alongside an experimental methodology to provide estimates by age and sex at a local level. They contain a degree of uncertainty that we are unable to quantify at this time. We will revise estimates of international migration as our methods develop. The official Northern Ireland estimates of international migration, produced by NISRA, and included in the UK figures already have National Statistics status.
For the UK as a whole, net international migration for the year to mid-2021 was an estimated 173,000 and for England and Wales it was an estimated 156,000. However, net international migration for the quarter of the year between April and June 2021, for England and Wales, was close to zero (an estimate of around 1,000). This reflects seasonal patterns in migration and covers the period where international travel was restricted following the coronavirus pandemic. Home Office statistics on passenger arrivals into the UK show that air travel began to recover from July 2021.
| Component | Estimate |
|---|---|
| Population of England and Wales, Census Day (21 March 2021) | 59,597,000 |
| Births in England and Wales | 171,000 |
| Deaths in England and Wales | 132,000 |
| Net international migration for England and Wales | 1,000 |
| Net internal migration for England and Wales | 5,000 |
| Mid-year population estimate for England and Wales | 59,642,000 |
Internal migration for England and Wales
In the period between Census day and mid-year 2021 we estimate that around 5,000 more people moved to England and Wales from the rest of the UK than left. This contrasts with most periods where a higher number of people move from England and Wales to other parts of the UK.
5.Upcoming population estimates
Rebasing and reconciliation
The Office for National Statistics (ONS) will conduct reconciliation work for mid-year population estimates to understand how and why the estimates based on Census 2021 for England and Wales differ from those based on the mid-year estimates rolled forward from the 2011 Census. The insights gained will be used to improve the production of future population estimates and will result in a revised back series of population estimates for the period 2012 to 2020. This back series will increase the coherence between the census and mid-year estimates. The provisional publication date is early 2023 for reconciliation and spring 2023 for rebasing.
The Northern Ireland Statistics and Research Agency (NISRA) will conduct reconciliation and rebasing work to understand how and why the estimates based on Census 2021 for Northern Ireland differ from those based on the mid-year estimates rolled forward from the 2011 census. Further information can be found in Mid-year population estimates for Northern Ireland: 2021.
Mid-2022 population estimates
We plan to publish population estimates for England and Wales in Summer 2023. The Northern Ireland Statistics and Research Agency (NISRA) also plan to release mid-2022 population estimates in Summer 2023. Details of its release plans can be found in its Population Statistics Work Plan.
Mid-2022 population estimates for Scotland will be based primarily on the results of the 2022 Census adjusted for births, deaths and migration in the period between census day and mid-year and are currently scheduled to be published in winter 2023 to 2024.
