Photo: Alan Hughes · CC BY-SA 2.0A larger share of residents with no religion than 98% of UK towns: 56%
Half of Sarn’s residents are under 41.4, younger than in 73% of UK towns. The 2021 Census counted 11,867 residents in 5,150 households. Adults who have never married account for 36%. Against a figure of 29% across Wales’s towns, the share of households in terraced houses in Sarn comes in at 25%.
Growth of +11% since 2011 puts Sarn ahead of 63% of UK towns
ONS mid-year estimates, each year indexed to mid-2011 = 100. Sarn’s figure is the small areas (2021 LSOAs) that make up the town.
People, mid-2011 = 100
Change by age, 2011 to 2024
About 11,400 people in 2011; 12,700 in 2024.
Change by age ran from +44% for the 65 and over to −6% for the 16 to 29. Mid-2018 to mid-2019 brought the biggest yearly rise, 240 people.
Residents aged 65 and over make up 18% in Sarn, less than in 77% of UK towns
Share of residents in each five-year age band, Census 2021.
The biggest five-year age group is 30–34, with 7.5% of residents. Residents aged 15 to 24 are more common here than in 70% of UK towns. Measured more widely, 21% of residents are 65 or over across Wales’s towns. In Porthcawl, the oldest of Mid Glamorgan’s towns by this measure, it is 33%.
Median age of UK towns of 2,500+
■ Sarn, 41.4. The typical town is 44.4.
Broad ages · share of residents
Women and men · all residents
51% women, 49% men
About 94 men for every 100 women. Across Wales, 51% of residents are women.
Residents who moved in within the year make up 6.7% in Sarn, less than in 89% of UK towns
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%.
Across Wales’s towns, 29% of adults are in managerial and professional jobs and 27% in routine work; in Sarn, 28% and 31%. The share of residents who moved in within the year across Wales’s towns is 9.1%. For Sarn, the census puts full-time students at 5.2%.
The Census was taken on 21 March 2021, in term time, so students were counted at their term addresses.
Households with dependent children make up 29% in Sarn, more than in 64% of UK towns
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.
Shared households of unrelated adults are about as common here as across Wales’s towns, at 2.6%. Measured more widely, 27% of households have dependent children across Wales’s towns. Census figures put one-person households at 30% in Sarn.
Sarn ranks above 66% of UK towns on households without a car or van: 18%
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
Against a figure of 24% across Wales’s towns, the share of households in detached houses in Sarn comes in at 22%. Still, more households in flats than in just over three fifths of UK towns: 13%. As a yardstick, 21% of households have no car or van across Wales’s towns.
Fewer residents born abroad than 78% of UK towns: 4%
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%
When those born abroad arrived
Main language · residents aged 3 and over
99% of residents have English as their main language; across Wales’s towns the figure is 96%. The wider picture: 7.4% of residents were born outside the UK across Wales’s towns. Among residents born abroad, the largest groups were born in EU countries (2.1%) and in the Middle East and Asia (0.9%).
Sarn’s residents: 9.1% speak Welsh
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
Against 16% across Welsh towns, 9.1% of residents aged 3 and over can speak Welsh here (1,045 people): fewer than in 78% of Welsh towns. In Mid Glamorgan, Pontyclun has the highest share (20%).
38% describe themselves as Christian, fewer than in 95% of UK towns
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: 95% of Sarn · Mid Glamorgan’s towns 95% · Wales’s towns 90%.
Religion · all residents
The share of residents who describe themselves as White British tops 78% of UK towns: 95%. After White British, the largest groups are Other White (2%), Mixed or multiple (1.1%) and Chinese (0.4%). Across the comparison, 43% of residents describe themselves as Christian across Wales’s towns.
A higher share of unpaid carers than 84% of UK towns, at 11%
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
Heavy unpaid care, 50 hours a week or more, falls to 405 residents. Lower than in 76% of UK towns: 44% of adults are married or in a civil partnership. The benchmark for unpaid carers across Wales’s towns: 10%.
Adults with a degree-level qualification: 28%
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
Degree-level qualifications cover 28% of adults in Sarn, 31% across Wales’s towns; 24% have no qualification, against 20%.
98th youngest of 432 UK towns of 8,000 to 16,000 people
Median age, Census 2021. Hover a dot for its students and residents born abroad; click for its page.
Aberystwyth is the youngest (25); Sidmouth the oldest (60.4). Nearest to Sarn in age: Newtown (41.4), Bargod (41.4), Royston (41.5) and West End and Chobham (41.5).
Sarn is younger than 4 of its 7 nearest neighbours
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 |
|---|---|---|---|---|---|
| Sarn | 11,867 | — | 41.4 | 18% | 29% |
| Pen-y-fai | 2,301 | 1.2 mi | 48.6 | 24% | 28% |
| Bettws | 2,237 | 1.9 mi | 37.4 | 16% | 32% |
| Llangeinor | 1,016 | 2.2 mi | 40.2 | 18% | 29% |
| Bridgend | 51,751 | 2.4 mi | 40.2 | 17% | 29% |
| Cefn Cribwr | 1,379 | 2.9 mi | 46.9 | 23% | 27% |
| Pont Rhyd-y-cyff | 1,481 | 3.6 mi | 47.7 | 26% | 24% |
| Pencoed | 9,119 | 3.7 mi | 45.5 | 23% | 28% |
Health, work and homes have their own pages
What this data can and can’t tell you
- The Census was taken in a lockdown, in term time. 21 March 2021 fell in term time, and students were asked to give their term-time address, so most were counted where they study. Some may have been living with family that day.
- “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 Sarn’s figures, so households in open countryside are left out. The population trend compares with the whole county and nation.
- Estimates since 2021 are modelled. The ONS builds mid-year estimates from the Census, births, deaths and migration records. Sarn’s trend uses the small areas (2021 LSOAs) with most of their people inside it: 12,501 people in 2021, against 11,867 in the built-up area.
- 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 Sarn’s residents
What is the population of Sarn?
The 2021 Census counted 11,867 people in Sarn’s built-up area. The ONS estimates the same small areas held 12,700 people in mid-2024, 11% more than in 2011.
What is the average age in Sarn?
The median age was 41.4 at the 2021 Census, younger than 73% of UK towns. 10% of residents were 15 to 24 and 18% were 65 or over.
How diverse is Sarn?
95% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 95% across Mid Glamorgan’s towns. 4% were born outside the UK.
What religion are people in Sarn?
56% said they had no religion and 38% that they were Christian at the 2021 Census; 0.3% were Muslim and 5.1% didn’t answer.
Is Sarn good for families?
29% of households had dependent children in 2021, against 27% across Wales’s towns. Schools are on Sarn’s schools page.
How many people speak Welsh in Sarn?
1,045 residents aged 3 and over, 9.1%, 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) · ONS mid-year population estimates for 2021 LSOAs, mid-2011 to mid-2024. 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.