Photo: Ruth Sharville · CC BY-SA 2.0A larger share of residents with no religion than 99% of UK towns: 58%
Households average 2.5 people, against 2.3 across Wales’s towns. Census day 2021: 630 residents and 258 households in Blackmill. On the census count, nearly a quarter of households are one person living alone. 6.6% of households live in a flat or apartment, a lower share than in 75% of UK towns.
Younger than 67% of UK towns: half of Blackmill is under 42.3
Share of residents in each five-year age band, Census 2021.
Just over one in ten residents are aged 15 to 24, against 12% across Wales’s towns. Here, just over a fifth of residents are 65 or over.
Broad ages · share of residents
Women and men · all residents
53% women, 47% men
About 90 men for every 100 women. Across Wales, 51% of residents are women.
Blackmill ranks below 90% of UK towns on full-time students: 3.8%
What adults did at the 2021 Census (the ONS’s NS-SEC classes), and where residents lived a year earlier.
Adults by occupation class · residents 16 and over
Address a year before the Census
Residents who lived somewhere else a year earlier. The bar runs to 25%.
Set against 9.1% across Wales’s towns, 6.7% of residents lived at another address a year earlier in Blackmill. Full-time students: 8% across Wales’s towns, for comparison.
Blackmill ranks above 80% of UK towns on households with dependent children: 31%
Household make-up at the 2021 Census. Each square is 1% of households.
Against Mid Glamorgan’s towns and Wales’s towns
People per household
Wales’s towns.
Across Wales’s towns, 3.1% of households are unrelated adults sharing a home; in Blackmill, 1.9%. As a yardstick, 27% of households have dependent children across Wales’s towns.
Above 81% of UK towns: 43% of households live in a detached house
Accommodation type and cars or vans per household, Census 2021. Owning and renting are on Cost of living.
Type of home
Cars or vans · share of households
Households without a car or van account for 15%. A fifth of households live in a terraced house, against 29% across Wales’s towns.
3.8% of residents were born outside the UK, below 80% of UK towns
Country of birth, year of arrival and main language, Census 2021.
Born outside the UK, by region · share of all residents; the bar runs to 10%
Main language · residents aged 3 and over
By birthplace, the largest groups from abroad were born in EU countries (2.2%) and in the Americas, Oceania and elsewhere (1%). Higher than in 77% of UK towns: 99% of residents have English as their main language. For residents born outside the UK, the comparison across Wales’s towns is 7.4%.
Welsh speakers: 10% of Blackmill’s residents
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
10% of residents aged 3 and over, 61 people, said in 2021 that they can speak Welsh, fewer than in 68% of Welsh towns (Welsh towns: 16%). Pontyclun leads Mid Glamorgan with 20%.
Below 96% of UK towns: 37% of residents describe themselves as Christian
How residents described themselves at the 2021 Census. Lines join the lowest and highest of the three figures.
Ethnic groups other than White British · all residents
White British, not charted: 96% of Blackmill · Mid Glamorgan’s towns 95% · Wales’s towns 90%.
Religion · all residents
Other than White British, most residents describe themselves as Other White (2.2%), Mixed or multiple (1.3%) and Pakistani (0.3%). Residents who describe themselves as Christian: 43% across Wales’s towns, for comparison. Blackmill has more residents who describe themselves as White British than 83% of UK towns, at 96%.
12% of residents give unpaid care, more than in 98% of UK towns
Legal partnership status (residents 16 and over) and unpaid care (residents 5 and over), Census 2021.
Partnership status · residents 16 and over
Unpaid care given · share of residents 5 and over
In Blackmill, 47% of adults are married or in a civil partnership, beside 43% across Wales’s towns. At 35%, the share of adults who have never married is higher than in just over two thirds of UK towns. Across Wales’s towns, the share of unpaid carers is 10%. Some 27 people give 50 hours or more of unpaid care a week.
Qualified to degree level: 25% of adults
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
Across Wales’s towns, 20% of adults have no qualification; in Blackmill, 26%, while 25% hold one at degree level (31%).
Blackmill and its 7 nearest towns: 2 of them are older
Nearby built-up areas coloured by median age, Census 2021. Tap a town for its page.
| Town | People | Away | Median age | 65+ | Homes with children |
|---|---|---|---|---|---|
| Blackmill | 630 | — | 42.3 | 21% | 31% |
| Llangeinor | 1,016 | 1.4 mi | 40.2 | 18% | 29% |
| Bettws | 2,237 | 2.2 mi | 37.4 | 16% | 32% |
| Ogmore Vale | 3,098 | 2.3 mi | 42.8 | 20% | 28% |
| Sarn | 11,867 | 2.7 mi | 41.4 | 18% | 29% |
| Gilfach Goch | 1,531 | 3.1 mi | 38.9 | 18% | 32% |
| Hendreforgan | 2,445 | 3.1 mi | 41.1 | 19% | 31% |
| Pencoed | 9,119 | 3.4 mi | 45.5 | 23% | 28% |
Health, work and homes have their own pages
What this data can and can’t tell you
- “Mid Glamorgan’s towns” and “Wales’s towns” mean their built-up areas. Census comparisons pool every built-up area in Mid Glamorgan (or Wales), summed the same way as Blackmill’s figures, so households in open countryside are left out.
- Small counts are blurred. The ONS adds small random changes to Census counts to protect privacy, so the same total differs a little between tables, and the shares of a small town can move by a point or two.
Questions about Blackmill’s residents
What is the population of Blackmill?
The 2021 Census counted 630 people in Blackmill’s built-up area.
What is the average age in Blackmill?
The median age was 42.3 at the 2021 Census. 11% of residents were 15 to 24 and 21% were 65 or over.
How diverse is Blackmill?
96% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 95% across Mid Glamorgan’s towns. 3.8% were born outside the UK.
What religion are people in Blackmill?
58% said they had no religion and 37% that they were Christian at the 2021 Census; 0.3% were Muslim and 5.3% didn’t answer.
Is Blackmill good for families?
31% of households had dependent children in 2021, against 27% across Wales’s towns. Schools are on Blackmill’s schools page.
How many people speak Welsh in Blackmill?
61 residents aged 3 and over, 10%, said they can speak Welsh at the 2021 Census, against 16% across Welsh towns.
Sources: ONS Census 2021, output areas summed to the ONS 2022 built-up area (TS002, TS003, TS004, TS007A, TS008, TS015, TS017, TS019, TS021, TS029, TS030, TS039, TS044, TS045, TS062, TS067, TS032). All under the Open Government Licence v3.0.
Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.