Skip to content

The Office for National Statistics produces annual estimates of the resident population as of 30 June each year. The estimates refer to the number of people who live in the UK as a whole, the constituent countries, and areas within England and Wales. They are provided by age and sex subgroups.

Publications

2011 Census
Department: Office for National Statistics
2011 Census statistics provide a rich source of information about the number, distribution and characteristics of the population in England and Wales. The statistics are used to understand similarities and differences in the population locally, regionally and nationally. This information underpins the allocation of billions of pounds of public money to provide services like education, transport and health. Decisions are taken every day using census statistics.
Annual Report of the Registrar General (Northern Ireland)
Department: Northern Ireland Statistics and Research Agency
Finalised data for all births, deaths, marriages, civil partnerships and divorces along with population data for the year in question.
Census 2001 First Results on Population in England and Wales
Department: Office for National Statistics
The First Results on Population in England and Wales report contains data for the United Kingdom, England and Wales, England, Wales, Scotland, Northern Ireland, and for all Government Office Regions, counties, Unitary Authorities, and local authorities in England and Wales. The report contains the first results from the 2001 Census - resident population at Census Day (29 April 2001) by sex and age.
Census 2001 First Results on Population in Wales
Department: Office for National Statistics
The First Results on Population in Wales bilingual report contains data for Wales as a whole and all Unitary Authorities in Wales. The report contains the first results from the 2001 Census - resident populations at Census Day (29 April 2001) by sex and age. This includes single year of age resident population figures for Wales and five year age band resident population figures for all people for unitary authorities in Wales.
Centenarians in Scotland
Department: National Records of Scotland
Provides information on the methodology and background of this work, along with the number of people aged 90 and over, by sex and single year of age.
Health Geography Population Estimates
Department: Office for National Statistics
This product is part of the set of Small Area Population Estimates (SAPE). It includes mid-year population estimates for health geographies in England, including Clinical Commissioning Groups (CCGs), NHS Area Teams, NHS Commissioning Regions and the former Primary Care Organisation (PCO) areas. These estimates are consistent with local authority, regional and national population estimates.
Key Population and Vital Statistics
Department: Office for National Statistics
Provides data on resident population, births, maternities, deaths, mortality and migration for local administrative areas and health areas throughout the UK.
Mid-Year Population Estimates for Northern Ireland
Department: Northern Ireland Statistics and Research Agency
Counts of the Northern Ireland population as at 30th June by sex and single year of age.
Mid-Year Population Estimates for Scotland
Department: National Records of Scotland
Population by age, sex and administration area (council and health board area).
Mid-Year Population Estimates, Wales
Department: Welsh Government
Provides estimates of population data.
Migration Statistics Improvement Programme Reports
Department: Office for National Statistics
The Migration Statistics Improvement Programme formally closes on 31 March 2012. Five reports are being published: Migration Statistics Improvement Programme Final Report A Conceptual Framework for Population and Migration Statistics Research report: Using administrative data to set plausibility ranges for population estimates in England and Wales Research Report: Uncertainty in Local Authority Mid Year Population Estimates Strategy for Delivering Statistical Benefits from e-Borders
National Park Population Estimates (experimental)
Department: Office for National Statistics
This product is part of the set of Small Area Population Estimates (SAPE) and includes estimates for National Parks in England and Wales.
Parliamentary Constituency Population Estimates (experimental)
Department: Office for National Statistics
Mid-year population estimates for Westminster Parliamentary Constituencies in England and Wales (part of the set of Small Area Population Estimates).
Population Estimates by Ethnic Group
Department: Welsh Government
This Statistical Bulletin shows data on population estimates by ethnic group for Welsh local authorities, by age and sex.
Population Estimates by Ethnic Group (experimental)
Department: Office for National Statistics
Population estimates by ethnic group for English and Welsh local authorities, by age and sex.
Population Estimates by Marital Status
Department: Office for National Statistics
Estimates of the usual resident population by marital status for England and Wales as at 30 June of the reference year. Provided by single year of age and sex.
Population Estimates for England and Wales
Department: Office for National Statistics
Estimates of the usual resident population for England and Wales as at 30 June of the reference year. Provided by administrative area, single year of age and sex.
Population Estimates for UK, England and Wales, Scotland and Northern Ireland
Department: Office for National Statistics
Estimates of the usual resident population for the UK as at 30 June of the reference year. Provided by administrative area, single year of age and sex.
Population Estimates of Persons Aged 85 and Over (Northern Ireland)
Department: Northern Ireland Statistics and Research Agency
Detailed estimates of the numbers of people aged 85 and over, by sex and age.
Population Estimates of the Very Elderly
Department: Office for National Statistics
Population of the very elderly (including centenarians) by gender, single year of age (90 to 104) and by age groups (90-99, 100+ and 105+) for the UK and England & Wales.
Population Trends
Department: Office for National Statistics
Population and demographic information. It contains commentary on the latest findings and topical articles on relevant subjects.
Population estimates by marital status for Scotland
Department: National Records of Scotland
Presents population estimates by marital status.
Primary Care Organisation Population Estimates (experimental)
Department: Office for National Statistics
Mid-year population estimates for Primary Care Organisations (former health areas) in England (part of the set of Small Area Population Estimates).
Provisional Population Statistics For New 11 Districts in Northern Ireland
Department: Northern Ireland Statistics and Research Agency
Provisional population figures for the new geographies (11 Districts) in Northern Ireland for mid 2011 to mid-2012.
Quality Report / User Guide – Northern Ireland Population Estimates
Department: Northern Ireland Statistics and Research Agency
Report describing the quality of mid-year population estimates in Northern Ireland using comparator data sources and demographic analysis
Scotland's Population: The Registrar General's Annual Review of Demographic Trends
Department: National Records of Scotland
Presents key findings from the Registrar General's Annual Review.
Small Area Population Estimates for Northern Ireland
Department: Northern Ireland Statistics and Research Agency
Counts of the Northern Ireland population at low level geography as at 30th June by sex and selected age groups
Small Area Population Estimates, Scotland
Department: National Records of Scotland
Small area population estimates for data zones.
Super Output Area mid-year population estimates for England and Wales (experimental)
Department: Office for National Statistics
Population estimates for lower and middle layer Super Output Areas (SOAs) in England and Wales by age and sex, revised in line with the results of the 2011 Census.
Wales's Population
Department: Welsh Government
Presents a comprehensive overview of demographic statistics for Wales.
Ward Level mid-year population estimates for England and Wales (experimental)
Department: Office for National Statistics
Mid-year population estimates for electoral wards in England and Wales (part of the set of Small Area Population Estimates).

Back to the top

Overview

Mid-year population estimates relate to the usually resident population of an area. Usual residence is the standard United Nations definition for population estimates and includes people who reside in the area for a period of at least 12 months. The usually resident population is not the same as the number of people to be found in an area at a particular time of the day or year. For example, the daytime population of city centres will be larger than their usually resident populations.  

Population estimates at local authority level are published annually and for a particular mid-year they become available around 14 months after the reference date.

The local authority estimates are broken down to provide estimates for other geographies such as Lower Layer and Middle Layer Super Output Areas, National Parks and wards. Other published population estimates at subnational levels include quarterly estimates, household population and estimates by ethnic group. Marital status estimates and estimates of the very elderly are published for England and Wales.

The statistics are used by central and local government and the health sector for planning, monitoring and resource allocation and are of interest to a wide range of users including: commercial companies, special interest groups, academia and the general public.

Back to the top

Technical Data

The estimated resident population of an area includes all people who usually live there, whatever their nationality. Visitors and short term-migrants (who enter or leave the UK for less than 12 months) are not included. Members of Her Majesty's Armed Forces and US Armed Forces stationed in England and Wales are included but members of Her Majesty's Armed Forces stationed outside England and Wales are excluded. Students are taken to be resident at their term-time address. For a minority of people the concept of usual residence is more difficult; homeless people would be included in the population estimates if counted in the previous Census but could be allocated to the wrong area if subsequent moves were not captured by the patient registers.

Most Office for National Statistics (ONS) population estimates, including the national and local authority estimates are made using the cohort component method. This is a standard demographic method in which information on the components of population change are used to update a population base such as the Census estimate. The resident population, by single year of age, on 30 June of the year prior to the reference year is aged on by one year; those born during the 12-month period prior to the mid-year are added on to the population and those who have died are removed.

Other factors taken into account are the movement of people into and out of the UK (international migration) and, for estimating the population for different areas within the UK, movements between areas of the UK (internal migration).

Some population subgroups such as prisoners, school boarders and armed forces (home and foreign) are estimated separately from the rest of the population. These groups are not covered by the data sources used for migration estimates and therefore their movements are not accounted for. In addition, the age structure of these population subgroups tends to remain constant over time so they are not aged forward.

Population estimates are calculated using a ‘top down’ approach. The national estimates for England and Wales are produced first; estimates for subnational areas are then produced and constrained to the national estimates. Further details of the methods used for population estimates are available on the National Statistics website.

The data sources used are the best available on a nationally consistent basis. Information from administrative registers such as the numbers of births and deaths is reliable. However, estimates of international migration are largely derived from the International Passenger Survey (IPS) and are subject to sampling and non-sampling error. National figures have relatively small levels of uncertainty, but at local level the sample counts in the IPS are small and it is necessary to combine data across years and/or local areas. International migration estimates at local authority level are made by distributing higher level estimates using other data sources.

To account for internal migration, NHS patient registers are used as changes in address are recorded. Although patient registers provide the best fit to the usually resident population, they have recognised limitations with regard to timeliness and coverage.

ONS is leading a substantial cross-government programme of work to improve population and migration statistics. The recommendations of the National Statistician’s Interdepartmental Task Force on Migration Statistics (2006) are being implemented through this work programme. Subsequent parliamentary reviews have endorsed the work programme. The programme includes work to estimate and describe the quality of population estimates.

Back to the top

Glossary

  • Asylum

    Protection given by a country to someone who is fleeing persecution in their own country.

  • Asylum Seeker

    A person who has entered the UK from another part of the world with the specific intention of applying for asylum.

  • Base Population

    The population resident at the end of the previous mid-year, or derived from the Census.

  • Census

    A survey of all people and households in the country. It provides essential information from national to neighbourhood level for government, business, and the community.

  • Cohort

    A well-defined group of people who have had a common experience or exposure who are observed through time. For example, all population born between the annual mid-year population estimates (1 July to 30 June) in a given reference year.

  • Components of population change

    Births, deaths, in-migrants and out-migrants.

  • Country

    In the context of mid-year estimates, 'country' means England, Wales, Scotland or Northern Ireland. An artefact that is 'by Country' will contain data for England and data for Wales, Scotland or Northern separately.

  • County

    The higher level administrative area in a two-tier local government structure.

  • County District

    Districts forming the lower level of local government within the two-tier local government structure remaining in parts of England after local government reorganisations (sometimes referred to as a local authority district).

  • Foreign Armed Forces

    Foreign Armed Forces stationed in England and Wales.

  • Foreign Armed Forces Dependants

    Dependants of Foreign Armed Forces stationed in England and Wales.

  • Government Office Region (GOR)

    Administrative areas in England for which regional government offices are responsible.

  • GRO(S)

    General Register Office (Scotland).

  • Health Areas

    These areas are Strategic Health Authorities (SHAs) and Primary Care Trusts (PCTs) in England and Local Health Boards (LHB) in Wales.

  • Home Armed Forces (HAF)

    UK Armed Forces stationed in England or Wales.

  • Inter-censal period

    The period between consecutive Census years.

  • International Migrant

    Someone who changes his or her country of usual residence for a period of at least one year, so that the country of destination effectively becomes the country of usual residence.

  • International Passenger Survey (IPS)

    The International Passenger Survey (IPS) is a survey of a random sample of passengers entering and leaving the UK by air, sea or the Channel Tunnel. Over a quarter of million face-to-face interviews are carried out each year with passengers entering and leaving the UK through the main airports, seaports and the Channel Tunnel.

  • Local authority

    A local government administrative area. Either a county district, unitary authority or London borough.

  • London Borough

    A single-tier of local government remaining in the former Greater London Council.

  • Migrant Switcher

    A person who leaves or enters the UK with the intention of staying for a period of at least one year, but does not realise this intention.

  • National population

    Population estimates are available for the following national geographies: UK, Great Britain, England and Wales, England, Wales, Scotland and Northern Ireland.

  • Natural Change

    The difference between the number of births and deaths within a defined period of time.

  • Net migration

    The difference between long term migrants entering the country and those leaving the country.

  • NHSCR

    National Heath Service Central Register.

  • Patient Register

    Details of the patients registered with GPs within an area. These include the NHS number, sex, date of birth, date of acceptance and the postcode of address for each patient.

  • Quinary Age Group

    Age bands that cover five years (0 to 4, 5 to 9, 10 to 14).

  • Reconciliation Adjustment

    An adjustment applied to ensure estimates for smaller geographies are consistent with those for higher geographies.

  • Reference Year

    The year for which the population estimate is being compiled. Mid-year population estimates are made for the population resident as at 30 June of the reference year. The year runs from 1 July to 30 June.

  • Resident Population

    The estimated population of an area includes all those usually resident in the area, whatever their nationality. Members of Her Majesty's Armed Forces stationed in England and Wales are included at their place of residence but those stationed outside England and Wales are not included. Members of the US Armed Forces stationed in England and Wales are included at their places of residence. Students are taken to be resident at their term-time address. Prisoners are regarded as usually resident at an institution if they have served six months or more of a custodial sentence. Diplomats are excluded.

  • Rounding Error

    When rounded sub-national figures do not equate to national figures (rounded) because of the accumulated loss/gain of fractions of population.

  • Service Families Abroad

    Civilian dependants of England and Wales share of UK Armed Forces stationed outside England and Wales.

  • Stationed Armed Forces

    UK and Foreign Armed Forces stationed in England and Wales. All home Armed Forces data are recorded at their stationed base rather than where they are resident.

  • Sub-national population estimates

    Population estimates are available on the following sub-national geographies:   England: Government Office Regions (GOR), current and former counties, Metropolitan Districts, London Boroughs, County Districts and Unitary Authorities, Strategic Health Authorities and Primary Care Organisations.   Wales: Unitary Authorities, Health Authorities and Local Health Boards.

  • SYOA

    Single Year Of Age data groupings.

  • UK Armed Forces

    UK Army, Navy and Airforce personnel.

  • Unitary Authority

    The single-tier of local government existing in some parts of England and all parts of Wales and Scotland.

  • Visitor Switchers

    A person who enters the UK as a visitor, and has subsequently stayed in the country for a period of at least one year.

Back to the top

Contact Details

For statistical enquiries about this topic, please contact:

Population enquiries service

Email: pop.info@ons.gsi.gov.uk

Telephone: +44 (0) 1329 444661

Back to the top