Population size and structure

Southampton's population size and structure

Understanding the size and structure of Southampton’s population and how it is changing is vital in estimating population need and for the planning and commissioning of services across the city. Data on Southampton’s population comes from a range of sources, using different methodologies for estimating the size and structure of the population and how this is projected to change in the future. These are summarised below, whilst links to the data and visualisation tools can be found in the resources section at the end of this page.

Residential population estimates

The Small Area Population Forecasts (SAPF) are produced annually by Hampshire County Council and estimate the size of the local resident population for Hampshire districts as well as Portsmouth and Southampton. These estimates are considered to provide the most robust local estimate of the current and future resident population as they take account of natural change (births and deaths), internal and international migration and known and planned dwelling completions. They also include future dwellings supply based on residential planning applications. Current forecasts run from 2021 to 2028. The SAPF data is available for Local Authorities, wards and Lower Level Super Output Areas (LSOAs), allowing the creation of defined smaller areas or community data. Detailed SAPF data and methodology documents can be found in the Population dashboard or in the resources section the end of the page. A summary of the main points is provided below:

• In 2021, the resident population of Southampton was estimated to be 261,729, of which 128,372 (49.0%) were female and 133,357 (51.0%) were male
• Children between the ages 0 to 5 make up 6.5% (17,008) of the population, which is similar to the national average of 6.9%
• 18.4% (48,216) of Southampton’s resident population is aged between 16 and 24 years compared to just 10.5% nationally. This is largely due to Southampton being a university city and home to approximately 43,000 students
• 14.6% of the population are aged over 65 (38,169 people) which is lower than the national average of 18.5%.
• Bargate ward has the largest population of 25,873 people or 9.9% of Southampton’s total population
• The smallest ward is Coxford with a population of 14,224 people or 5.4% of Southampton’s population
• Bargate (34.9%) and Swaythling (34.0%) have the largest populations aged 16-24 reflecting the large student population in Southampton
• The overall resident population is projected to increase by 6.3% between 2021 and 2028
• Bargate ward is forecast to increase by 23.7% between 2021 and 2028, but Bitterne ward is forecast to decrease by -1.1% in the same period
• There were an estimated 108,332 dwellings in Southampton in 2021

Mid-year population estimates (MYE)

Alternative resident population estimates are produced by the Office for National Statistics (ONS). These are known as the ONS Mid-year population estimates (MYE) and are useful as they provide comparable trend data across the whole country. These estimates are produced annually and are calculated by rolling forward the previous Census results (currently 2011), taking into account natural change (births and deaths) and internal and international migration between 1 July and 30 June each year.

The latest MYE (2020) suggests that Southampton’s population is 252,872 residents of which 123,203 (48.7%) were female and 129,669 (51.3%) were male. It also shows that the resident population of the city is estimated to have grown by 8.5% since 2010; that is an extra 19,787 people. More information on the ONS MYE can be found in the population dashboard and resources section below.

Subnational population projections (SNPP)

These projections take the mid-2018 population estimates, published on 26 June 2019, as their starting point and project the population to 2043. The projected local authority populations for each year are calculated by ageing on the population from the previous year, applying local fertility and mortality rates to calculate the number of projected births and deaths, and then adjusting for migration into and out of each local authority.

The latest SNPP data runs from 2018 to 2043 and suggests that Southampton’s population is estimated to be 270,834 in 2043, an increase of 7.1% or 18,038 people. More details can be found in the population change section and in the population dashboard and resources section below.

GP registered population

An alternative source of population data comes from GP practice registers; these provide the number of patients registered with a Southampton GP practice. The registered population differs from the resident population as a person can be registered with a Southampton GP practice but live outside the city, or may live in the city, but be registered with a GP practice outside of Southampton. For this reason, the registered population can be quite different to the resident populations. However, this information is particularly useful for the planning of health services.

NHS Digital collates the registered population at GP practice, Clinical Commissioning Group (CCG) and Lower Super Output Area (LSOA) level. The data is available by age and gender and is released monthly. In January 2023, there were 316,129 people registered at a Southampton GP, of which 153,352 (48.5%) were female and 162,777 (51.5%) were male. This is 20.8% higher than the estimated resident population (261,729 people). More information is available in the population dashboard and the resources section below.