Photo: Eric Jones · CC BY-SA 2.0A median age of 51.4: Rhostrehwfa is older than 91% of UK towns
Here 74% of households live in a detached house, where the figure across Wales’s towns is 24%. The 2021 Census put Rhostrehwfa’s population at 546, in 223 households. The census found that 98% of residents describe themselves as White British locally. Households in flats are rarer here than in 99% of UK towns.
26% of residents are 65 or over, more than in 79% of UK towns
Share of residents in each five-year age band, Census 2021.
The biggest five-year age group is 50–54, with one in ten residents, 1.4 times the share across Wales’s towns. Rhostrehwfa has fewer residents aged 15 to 24 than 72% of UK towns, at 9.1%. Across the comparison, 21% of residents are 65 or over across Wales’s towns.
Broad ages · share of residents
Women and men · all residents
48% women, 52% men
About 107 men for every 100 women. Across Wales, 51% of residents are women.
3.1% of residents lived at another address a year earlier, below 99% 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%.
With full-time students at 5.7%, Rhostrehwfa is ahead of 79% of UK towns on that count. For residents who moved in within the year, the comparison across Wales’s towns is 9.1%.
The Census was taken on 21 March 2021, in term time, so students were counted at their term addresses.
Rhostrehwfa sits below 94% of UK towns for one-person households (23%)
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.
On shared households of unrelated adults, 4% here is much the same as across Wales’s towns. 22% of households have dependent children, a lower share than in 88% of UK towns. Across Wales’s towns, one-person households come to 32%. A household here holds 2.4 people on average.
Households without a car or van make up 7.9% in Rhostrehwfa, less than in 92% 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
10% of households live in a terraced house, against 29% across Wales’s towns. For households without a car or van, the comparison across Wales’s towns is 21%.
Below 99% of UK towns: 0.6% of residents were born outside the UK
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
Against a figure of 96% across Wales’s towns, the share of residents whose main language is English in Rhostrehwfa comes in at 100%. The largest groups were born in EU countries (0.2%) and in Africa (0.2%). Across Wales’s towns, residents born outside the UK come to 7.4%.
Of Rhostrehwfa’s residents, 74% can speak Welsh
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
Welsh speakers number 398, or 74% of residents aged 3 and over, against 16% across Welsh towns: more than in 97% of them. In Gwynedd, Caernarfon has the highest share (82%).
60% of residents describe themselves as Christian, more than in 94% 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: 98% of Rhostrehwfa · Gwynedd’s towns 93% · Wales’s towns 90%.
Religion · all residents
Here 34% of residents said they have no religion, where the figure across Wales’s towns is 47%. Set beside that, 43% of residents describe themselves as Christian across Wales’s towns.
In Rhostrehwfa, 55% of adults are married or in a civil partnership, more than in 87% 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
Where 38% of adults have never married or formed a civil partnership across Wales’s towns, Rhostrehwfa has 30%. The share of unpaid carers stands at 12%. The comparison figure for married adults and civil partners is 43% across Wales’s towns.
38% of adults have qualifications at degree level
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
With 38% of its adults qualified to degree level, Rhostrehwfa compares with 31% across Wales’s towns; another 15% hold no qualification (20%).
Median age: 2 of the 7 towns around Rhostrehwfa 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 |
|---|---|---|---|---|---|
| Rhostrehwfa | 546 | — | 51.4 | 26% | 22% |
| Llangefni | 5,264 | 1.7 mi | 39.5 | 20% | 31% |
| Gaerwen | 1,277 | 3.3 mi | 39.8 | 19% | 30% |
| Llanerchymedd | 1,155 | 6 mi | 44.3 | 21% | 30% |
| Llanfair Pwllgwyngyll | 2,905 | 6 mi | 52 | 33% | 22% |
| Y Felinheli | 2,333 | 7 mi | 42.9 | 21% | 25% |
| Benllech | 2,072 | 7.1 mi | 62 | 45% | 13% |
| Bodedern | 1,193 | 7.3 mi | 41.2 | 20% | 29% |
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 Rhostrehwfa’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 Rhostrehwfa’s residents
What is the population of Rhostrehwfa?
The 2021 Census counted 546 people in Rhostrehwfa’s built-up area.
What is the average age in Rhostrehwfa?
The median age was 51.4 at the 2021 Census. 9.1% of residents were 15 to 24 and 26% were 65 or over.
How diverse is Rhostrehwfa?
98% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 93% across Gwynedd’s towns. 0.6% were born outside the UK.
What religion are people in Rhostrehwfa?
34% said they had no religion and 60% that they were Christian at the 2021 Census; 0% were Muslim and 5.5% didn’t answer.
Is Rhostrehwfa good for families?
22% of households had dependent children in 2021, against 27% across Wales’s towns. Schools are on Rhostrehwfa’s schools page.
How many people speak Welsh in Rhostrehwfa?
398 residents aged 3 and over, 74%, 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.