Photo: M J Richardson · CC BY-SA 2.0A Welsh-speaking town: 36% of Carmarthen’s residents speak Welsh
By its share of households without a car or van (24%), Carmarthen is above 86% of UK towns. 16,448 residents in 7,454 households: that is Carmarthen at the 2021 Census. One-person households account for 37%. The median age here is 40.3, lower than in 79% of UK towns.
What the Census says about Carmarthen’s people
A Welsh-speaking town
5,706 residents, 36% of those aged 3 and over, said they can speak Welsh in 2021, more than in 84% of Welsh towns. Welsh language ↓
Written from the data on this page: ONS Census 2021 (output areas summed to the 2022 built-up area) and ONS mid-year population estimates.
Carmarthen’s population moved +7% on 2011, less than in 54% of UK towns
ONS mid-year estimates, each year indexed to mid-2011 = 100. Carmarthen’s figure is the small areas (2021 LSOAs) that make up the town.
People, mid-2011 = 100
Change by age, 2011 to 2024
About 16,600 people in 2011; 17,700 in 2024.
Mid-2022 to mid-2023 brought the biggest yearly rise, 200 people. Change by age ran from +20% for the 30 to 44 to −14% for the 16 to 29.
Carmarthen ranks above 91% of UK towns on residents aged 15 to 24: 12%
Share of residents in each five-year age band, Census 2021.
No age band is larger than 30–34: 6.8% of residents. At 21%, the share of residents aged 65 and over is lower than in 57% of UK towns. In Saundersfoot, the oldest of Dyfed’s towns by this measure, it is 39%.
Median age of UK towns of 2,500+
■ Carmarthen, 40.3. The typical town is 44.4.
Broad ages · share of residents
Women and men · all residents
52% women, 48% men
About 93 men for every 100 women. Across Wales, 51% of residents are women.
Full-time students: 7.9%, a higher share than 93% 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%.
Residents who moved in within the year make up 10%, close to the figure across Wales’s towns. Across Wales’s towns, full-time students come to 8%.
The Census was taken on 21 March 2021, in term time, so students were counted at their term addresses.
2.2 people per household, fewer than in 82% of UK towns
Household make-up at the 2021 Census. Each square is 1% of households.
Against Dyfed’s towns and Wales’s towns
People per household
Wales’s towns.
The share of households with dependent children stands at 27%. 2.4% of households are unrelated adults sharing a home, a higher share than in 56% of UK towns.
17% of households live in a flat or apartment, more than in 77% of UK towns
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 29% across Wales’s towns, the share of households in terraced houses in Carmarthen comes in at 24%. Households in flats make up 14% across Wales’s towns.
More residents born outside the UK than 70% of UK towns: 9.1%
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 15%
When those born abroad arrived
Main language · residents aged 3 and over
95% of residents have English as their main language, against 96% across Wales’s towns. The two biggest birthplaces abroad are in EU countries (4.2%) and in the Middle East and Asia (3%). To put it in context, 7.4% of residents were born outside the UK across Wales’s towns.
Welsh in Carmarthen: 36% of residents speak it
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
The 2021 Census found 5,706 Welsh speakers aged 3 and over, 36% of that age group, against 16% across Welsh towns: more than in 84% of them. No town in Dyfed beats Tumble (62%).
47% of residents describe themselves as Christian, fewer than in 65% 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: 89% of Carmarthen · Dyfed’s towns 93% · Wales’s towns 90%.
Religion · all residents
The share of residents who describe themselves as White British trails 69% of UK towns: 89%. By way of comparison, 43% of residents describe themselves as Christian across Wales’s towns. After White British, the largest groups are Other White (5%), Mixed or multiple (1.4%) and Indian (1%). Residents with no religion are more common here than in 61% of UK towns.
Carmarthen sits below 92% of UK towns for married adults and civil partners (40%)
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
487 people care, unpaid, for 50 hours or more a week. Higher than in 89% of UK towns: 40% of adults have never married or formed a civil partnership. As a reference point, 43% of adults are married or in a civil partnership across Wales’s towns. Unpaid carers: 9.2%, near enough the figure across Wales’s towns.
A degree-level qualification for 36% of adults
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
At degree level, Carmarthen counts 36% of its adults, against 31% across Wales’s towns; at the other end, 18% have no qualification (20%). The highest qualification of 15% is A levels, often students still at university.
From a median age of 36 in Carmarthen West & Cynwyl Elfed to 46 in Carmarthen South & Llangynnwr
The town’s 3 neighbourhoods (ONS middle-layer areas with 500+ residents inside it, named by the House of Commons Library), youngest first. Census 2021.
Carmarthen South & Llangynnwr is the oldest area, with 28% aged 65 or over; Carmarthen West & Cynwyl Elfed the youngest (median age 36). Families with children are most common in Carmarthen West & Cynwyl Elfed (33% of households).
49th youngest of 322 UK towns of 12,000 to 22,000 people
Median age, Census 2021. Hover a dot for its students and residents born abroad; click for its page.
The youngest is Aberystwyth (25) and the oldest Sidmouth (60.4). Nearest to Carmarthen in age: Stotfold (40.3), Hersham (40.3), Tonypandy (40.3) and Adwick le Street (40.4).
Carmarthen sits below 6 of its 7 closest neighbours on median age
Nearby built-up areas coloured by median age, Census 2021. Tap a town for its page.
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.
- “Dyfed’s towns” and “Wales’s towns” mean their built-up areas. Census comparisons pool every built-up area in Dyfed (or Wales), summed the same way as Carmarthen’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. Carmarthen’s trend uses the small areas (2021 LSOAs) with most of their people inside it: 17,252 people in 2021, against 16,448 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 Carmarthen’s residents
What is the population of Carmarthen?
The 2021 Census counted 16,448 people in Carmarthen’s built-up area. The ONS estimates the same small areas held 17,700 people in mid-2024, 7% more than in 2011.
What is the average age in Carmarthen?
The median age was 40.3 at the 2021 Census, younger than 79% of UK towns. 12% of residents were 15 to 24 and 21% were 65 or over.
How diverse is Carmarthen?
89% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 93% across Dyfed’s towns. 9.1% were born outside the UK.
What religion are people in Carmarthen?
43% said they had no religion and 47% that they were Christian at the 2021 Census; 1.8% were Muslim and 6% didn’t answer.
Is Carmarthen good for families?
27% of households had dependent children in 2021, against 27% across Wales’s towns. Families are most common in Carmarthen West & Cynwyl Elfed (33% of households). Schools are on Carmarthen’s schools page.
How many people speak Welsh in Carmarthen?
5,706 residents aged 3 and over, 36%, 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 · House of Commons Library MSOA names. 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.