Annual estimates of the population living in West Sussex are provided for a range of geographies (e.g. output area, ward, district, CCG, county, region, and country). National and local authority estimates are usually updated in June each year by the Office for National Statistics for the previous year (e.g. mid-2024 estimates were released in June 2025), with small area population estimates released later in the year, usually in November.
Population Estimates 2016 Briefing (PDF, 692Kb). This short pdf summarises the 2024 Mid-year population estimates. More detail can be read below:
In 2024, 915,037 people were estimated to be resident in West Sussex. TThis was 11,004 more than in 2023, an increase of 1.2%. In the period from mid-2021 to mid-2024, the population estimate of West Sussex increased by 3.4%. • In both 2023 and 2024, population growth was driven entirely by net migration, as natural change was negative in 2024 (7,713 births vs. 9,702 deaths, resulting in a net decrease of 1,989). Net internal migration increased from 5,372 in 2023 to 6,699 in 2024, while net international migration rose from 5,115 to 6,326. Internal migration remains the largest single contributor to population growth in West Sussex.
The median age provides a useful summary measure of the age structure of the population as it shows that exactly half the population is below the median age and the other half is above the median age. In West Sussex, the median age in 2024 was 44.7 years, unchanged from both 2023 and 2016. By comparison, the median age in England in 2024 was 40.2 years, which is lower than that of West Sussex.
Please note: we are currently updating the West Sussex JSNA site so please check back soon for updates.