Photo: Nilfanion · CC BY-SA 4.0A Welsh-speaking town: 82% of Caernarfon’s residents speak Welsh
Where 38% of adults have never married or formed a civil partnership across Wales’s towns, Caernarfon has 43%. At the 2021 Census, 9,831 people lived locally, in 4,372 households. Here, just over a third of households live in a terraced house. One-person households are more common here than in 88% of UK towns.
What the Census says about Caernarfon’s people
A Welsh-speaking town
7,731 residents, 82% of those aged 3 and over, said they can speak Welsh in 2021, more than in 99% 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.
A +8% change since 2011: Caernarfon grew faster than 51% of UK towns
ONS mid-year estimates, each year indexed to mid-2011 = 100. Caernarfon’s figure is the small areas (2021 LSOAs) that make up the town.
People, mid-2011 = 100
Change by age, 2011 to 2024
About 9,600 people in 2011; 10,300 in 2024.
The largest rise in a single year came from mid-2022 to mid-2023: 190 people. Of the age groups, 30 to 44 changed most (+20%) and 45 to 64 least (−2%).
Caernarfon is younger than 82% of UK towns: a median age of 39.6
Share of residents in each five-year age band, Census 2021.
Across Wales’s towns, the share of residents aged 65 and over is 21%; Caernarfon has 19%. Residents aged 15 to 24: 11% of the total.
Median age of UK towns of 2,500+
■ Caernarfon, 39.6. 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.
In Caernarfon, 5.8% of adults are full-time students, more than in 80% 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%.
29% of Caernarfon’s adults are in managerial and professional jobs and 30% in routine and semi-routine work, against 29% and 27% across Wales’s towns. Against that, 8% of adults are full-time students across Wales’s towns. Locally, nearly one in ten residents lived at another address a year earlier.
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 69% of UK towns
Household make-up at the 2021 Census. Each square is 1% of households.
Against Gwynedd’s towns and Wales’s towns
People per household
Wales’s towns.
28% of households have dependent children, against 27% across Wales’s towns. Shared households of unrelated adults are more common here than in 72% of UK towns.
Caernarfon ranks above 90% of UK towns on households without a car or van: 27%
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
15% of households live in a flat or apartment; across Wales’s towns the figure is 14%. Elsewhere, 21% of households have no car or van across Wales’s towns. Locally, 18% of households live in a detached house.
Fewer residents born abroad than 75% of UK towns: 4.2%
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
Among those born abroad, the share arriving in 2017 or later is 23% (Wales’s towns: 23%). For residents born outside the UK, the comparison across Wales’s towns is 7.4%. The largest groups were born in EU countries (2.4%) and in the Middle East and Asia (0.9%). Caernarfon has more residents whose main language is English than 55% of UK towns, at 98%.
82% of Caernarfon’s residents can speak Welsh
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
Some 7,731 people here aged 3 and over said in 2021 that they can speak Welsh, 82% of the total, against 16% across Welsh towns: more than in 99% of them. It is the highest share of Gwynedd’s 13 towns of 2,500+.
A lower share of residents who describe themselves as Christian than 75% of UK towns, at 46%
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 Caernarfon · Gwynedd’s towns 93% · Wales’s towns 90%.
Religion · all residents
The share of residents with no religion tops 83% of UK towns: 46%. Census figures put residents who describe themselves as White British at 95% in Caernarfon. For comparison, 43% of residents describe themselves as Christian across Wales’s towns.
Fewer married adults and civil partners than 96% of UK towns: 37%
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
Students and young renters account for much of that. Unpaid care takes 50 hours a week or more for 307 people. Compared with other places, unpaid carers are scarce here: 8.5%, fewer than in 72% of UK towns. Add to that, 43% of Caernarfon’s adults have never married or formed a civil partnership and 37% are married, against 38% and 43% across Wales’s towns.
Degree level: the highest qualification of 33% of adults
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
With 33% of its adults qualified to degree level, Caernarfon compares with 31% across Wales’s towns; another 21% hold no qualification (20%).
Of 413 UK towns its size (7,000 to 13,000 people), the 49th youngest
Median age, Census 2021. Hover a dot for its students and residents born abroad; click for its page.
Tidworth is the youngest (28.4); Seaton the oldest (61). Nearest to Caernarfon in age: Harworth and Bircotes (39.6), Sileby (39.6), Buntingford (39.7) and Bolton upon Dearne (39.8).
6 of the 7 nearest towns are older than Caernarfon
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 |
|---|---|---|---|---|---|
| Caernarfon | 9,831 | — | 39.6 | 19% | 28% |
| Bethel | 1,091 | 3.1 mi | 44.7 | 24% | 32% |
| Llanrug | 1,537 | 3.2 mi | 41.2 | 22% | 34% |
| Y Felinheli | 2,333 | 3.8 mi | 42.9 | 21% | 25% |
| Clwt-y-bont | 1,385 | 5.6 mi | 39 | 17% | 31% |
| Gaerwen | 1,277 | 5.7 mi | 39.8 | 19% | 30% |
| Llanberis | 1,838 | 5.8 mi | 44.5 | 20% | 25% |
| Penygroes | 1,793 | 6 mi | 45.2 | 24% | 24% |
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.
- “Gwynedd’s towns” and “Wales’s towns” mean their built-up areas. Census comparisons pool every built-up area in Gwynedd (or Wales), summed the same way as Caernarfon’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. Caernarfon’s trend uses the small areas (2021 LSOAs) with most of their people inside it: 10,076 people in 2021, against 9,831 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 Caernarfon’s residents
What is the population of Caernarfon?
The 2021 Census counted 9,831 people in Caernarfon’s built-up area. The ONS estimates the same small areas held 10,300 people in mid-2024, 8% more than in 2011.
What is the average age in Caernarfon?
The median age was 39.6 at the 2021 Census, younger than 82% of UK towns. 11% of residents were 15 to 24 and 19% were 65 or over.
How diverse is Caernarfon?
95% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 93% across Gwynedd’s towns. 4.2% were born outside the UK.
What religion are people in Caernarfon?
46% said they had no religion and 46% that they were Christian at the 2021 Census; 0.5% were Muslim and 6.6% didn’t answer.
Is Caernarfon good for families?
28% of households had dependent children in 2021, against 27% across Wales’s towns. Schools are on Caernarfon’s schools page.
How many people speak Welsh in Caernarfon?
7,731 residents aged 3 and over, 82%, 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.