How the figures are produced

This page is a placeholder. It will explain the geography, ward methods and comparisons in plain English, based on docs/geography.md.

Ward boundaries

Ward figures use the May 2025 ward boundaries, which are the same as the current (May 2026) wards in West Sussex.

Figures estimated from neighbourhood data

Some figures are published only for small neighbourhoods (lower layer super output areas, or LSOAs) of about 1,500 people. Each neighbourhood is counted in the ward that contains most of its population. Where a ward’s boundary cuts across neighbourhoods, its figure includes some people from neighbouring wards or misses some of its own, so the figure is approximate.

We measure how well each ward’s neighbourhoods match its boundary. Where less than 80% of the ward’s people are correctly placed, the ward page says the figure is approximate.

Figures built from Census output areas

Some Census 2021 figures are built for wards by adding up the smallest Census areas (output areas, about 130 households each) that fall in each ward. The figures for districts, West Sussex, the South East and England are the ones ONS publishes.

ONS makes small changes to small-area Census counts to protect people’s privacy, so ward figures may not add up exactly to the published district figures. The difference is tiny: at most a few dozen households in a district.