How England & Wales is changing, in the numbers.

Based Data is an independent, data-led picture of demographic change across England & Wales. Every figure on the site comes straight from official statistics — nothing is spun, and the only estimates are the projections, which say so plainly.

What it shows

The national dashboard and a page for each of the 331 local authorities put the same measures side by side: the White British share of the population, the foreign-born share, the make-up of school pupils, the ethnic and Muslim composition, and a projection of the White British share to 2051. Each headline carries the census trend behind it, back to 1991, so you can see the direction of travel rather than a single snapshot.

Where the numbers come from

• ONS Census, 1991–2021 — population, ethnicity, country of birth, religion and main language, harmonised to today's local-authority boundaries.
• DfE school census — pupil ethnicity and first language, year by year.
• ONS births — births by parents' country of birth.
• Home Office — the register of licensed visa sponsors and asylum support figures.

How the figures are built

National totals are population-weighted roll-ups of the local-authority data. The 2051 projection uses a cohort-component model where the inputs exist, and otherwise simply continues each area's own 2011–2021 census trend — always labelled as a projection, never as a fact. Where an area's data is reported at county level or its boundary changed after 2021, the affected figure is shown as unavailable rather than guessed. Visa-sponsor counts per area are approximate, as many records give only “London” for the town.

Independence

Based Data is not affiliated with the ONS, the Home Office, or any government body, and is not endorsed by them. We do our best to reproduce the source data faithfully; if you spot an error, please tell us on X and we'll fix it.

The data pipeline and hosting are paid for out of pocket. If the site is useful to you, you can buy me a coffee — it keeps the project running and independent. ← Back to the dashboard