Population density
People per square kilometre: the census population divided by the area inside the boundary.
Worked out by Open Index from census population counts and the area of each place
- Level of detail
- Output area
- Published for
- Nation, Region, Council, Constituency, Ward, Middle area, Neighbourhood and Output area
- Covers
- All four nations
- Updates
- Every 10 years
- Latest period
- 2021
- Published
- 21 July 2026
- Fetched by Open Index
- 15 October 2026
- Licence
- Open Government Licence 3.0
Where it covers
- England
- Wales
- Scotland
- Northern Ireland
- England178,604 of 178,605 output areas have a figure
- Wales10,275 of 10,275 output areas have a figure
- Scotland46,361 of 46,363 output areas have a figure
3 output areas have no figure for 2021. The map hatches each one and gives the reason.
- The published outline of this area covers almost no land, so a density would mislead.; Scotland's census was held a year later than in the rest of the UK, on 20 March 2022. This figure is for that day. Output area in City Centre South - 01, Output area in City Centre South - 01
- The published outline of this area covers almost no land, so a density would mislead. Output area in Nottingham 039B
How it is made
Worked out by Open Index from census population counts and the area of each place.
The census count of usual residents divided by the area inside the area's boundary in square kilometres, measured by Open Index from the full-resolution outline the map draws. Wards and constituencies use their best-fit census counts.
Rates for larger areas are worked out again from their own counts and populations, never averaged from output areas.
Zoom in past output area level and the map keeps the output area shapes and says so, rather than inventing detail.
- Nation2021 only
- Region2021 only
- Council2021 only
- Constituency2021 only
- Ward2021 only
- Middle area2021 only
- Neighbourhood2021 only
- Output area2021 only
Before you use it
- The area is everything inside the boundary, including parks, rivers and lakes, so places with large green spaces or water look less dense.
- Output areas are drawn tightly around homes. A few cover a single block of flats, so their density is very high.
- England, Wales and Northern Ireland held their census on 21 March 2021. Scotland's was a year later, on 20 March 2022, so its figures describe a day a year on.
- Each census office makes small random changes to counts to protect privacy, so the smallest areas can be a few people out, and small areas do not add up exactly to larger ones.
- Wards and constituencies are worked out by Open Index by adding up the census areas that best fit them, so they are close but not exact. Councils whose boundaries changed after the census are added up from output areas.
- Scotland's census publishes output areas and Data Zones in bulk, so Open Index adds up Data Zones for Intermediate Zones, councils and Scotland.
- Northern Ireland has no 2021 output areas. Its smallest census areas are Data Zones, so the map holds at that level there.
- No density is shown for an area whose published outline covers almost no land (under 100 square metres).
Colours on the map
Fixed breaks, held for every period, so colours mean the same over time.
How Open Index describes it
Page text on Open Index comes from this layer’s sentence rules, filled in with published figures. For Hackney:
Hackney had 13,611 people per square kilometre at the census.
In London the figure is 5,593 per km².
Worked out by Open Index from census population counts and the area of each place.
Sources and licences
- Edition
- Census 2021 topic summaries (Nomis bulk)
- Published
- 19 January 2023
- Fetched by Open Index
- 15 October 2026
- Licence
- Open Government Licence 3.0
- Edition
- Scotland's Census 2022 bulk tables, July 2026
- Published
- 21 July 2026
- Fetched by Open Index
- 15 October 2026
- Licence
- Open Government Licence 3.0
- Edition
- Census 2021 Flexible Table Builder extract, October 2026
- Fetched by Open Index
- 15 October 2026
- Licence
- Open Government Licence 3.0
Credit the calculation as: Worked out by Open Index from census population counts and the area of each place.