Photo: Bill Harrison · CC BY-SA 2.0A Welsh-speaking town: 72% of Porthmadog’s residents speak Welsh
With one-person households at 41%, Porthmadog is ahead of 99% of UK towns on that count. Census figures put married adults and civil partners at 38% locally. The median age in the town is 48.3, higher than in 76% of UK towns. The town’s 1,176 households held 2,579 residents at the 2021 Census.
What the Census says about Porthmadog’s people
A Welsh-speaking town
1,799 residents, 72% of those aged 3 and over, said they can speak Welsh in 2021, more than in 97% of Welsh towns. Welsh language ↓
Many older residents
28% of residents were 65 or over in 2021, more than in 86% of UK towns; 22% of households are someone 66 or over living alone. Ages ↓
Written from the data on this page: ONS Census 2021 (output areas summed to the 2022 built-up area).
28% of residents are 65 or over, a share 86% of UK towns don’t reach
Share of residents in each five-year age band, Census 2021.
Set against 12% across Wales’s towns, just over one in ten residents are aged 15 to 24 in Porthmadog. For comparison, 21% of residents are 65 or over across Wales’s towns. The biggest five-year age group is 70–74, with 7% of residents.
Median age of UK towns of 2,500+
■ Porthmadog, 48.3. The typical town is 44.4.
Broad ages · share of residents
Women and men · all residents
51% women, 49% men
About an even split. Across Wales, 51% of residents are women.
Full-time students: 5.4%, a higher share than 71% 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 Porthmadog, 24% and 32%. For full-time students, the comparison across Wales’s towns is 8%. The share of residents who moved in within the year stands at 9%.
The Census was taken on 21 March 2021, in term time, so students were counted at their term addresses.
22% of households have dependent children, below 90% 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.
3.2% of households are unrelated adults sharing a home, about the same as across Wales’s towns. Across Wales’s towns, households with dependent children come to 27%. Average household size: 2.1 people.
Households in terraced houses make up 47% in Porthmadog, more than in 97% 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
21% of households have no car or van, about the same as across Wales’s towns. As a yardstick, 29% of households live in a terraced house across Wales’s towns. On the census count, 18% of households live in a flat or apartment. Compared with other places, households in detached houses are scarce here: 15%, fewer than in 84% of UK towns.
Only 4.9% of residents were born outside the UK in Porthmadog
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 residents born abroad, the largest groups were born in EU countries (2.7%) and in the Middle East and Asia (1.4%). Across the comparison, 7.4% of residents were born outside the UK across Wales’s towns. Since 2017: 21% of those born abroad, against 23% across Wales’s towns.
Welsh, spoken by 72% of Porthmadog’s residents
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
Against 16% across Welsh towns, 72% of residents aged 3 and over can speak Welsh here (1,799 people): more than in 97% of Welsh towns. In Gwynedd, Caernarfon has the highest share (82%).
Below 75% of UK towns: 46% 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: 94% of Porthmadog · Gwynedd’s towns 93% · Wales’s towns 90%.
Religion · all residents
After White British, the largest groups are Other White (3.4%), Mixed or multiple (1.1%) and Chinese (0.3%). 44% of residents said they have no religion, more than in 69% of UK towns. As a yardstick, 43% of residents describe themselves as Christian across Wales’s towns. Residents who describe themselves as White British make up 94%, against 90% across Wales’s towns.
Unpaid carers: 7.4%, a lower share than 93% 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
Unpaid carers giving 50 hours or more a week: 64. The benchmark for unpaid carers across Wales’s towns: 10%. On adults who have never married, Porthmadog sits higher than 82% of UK towns: 38%.
Qualified to degree level: 28% of adults
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
Degree-level qualifications cover 28% of adults in Porthmadog, 31% across Wales’s towns; 19% have no qualification, against 20%.
Ranked by age, 81st oldest of 219 UK towns this size
Median age, Census 2021. Hover a dot for its students and residents born abroad; click for its page.
Ages run from 20.6 in Keele to 60.8 in St Mary's Bay. Nearest to Porthmadog in age: Seghill (48.2), Mancetter and Witherley (48.2), Harbury (48.4) and Ash (Dover) (48.4).
Porthmadog is younger than 2 of its 5 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 |
|---|---|---|---|---|---|
| Porthmadog | 2,579 | — | 48.3 | 28% | 22% |
| Penrhyndeudraeth | 1,463 | 2.8 mi | 45.6 | 23% | 25% |
| Criccieth | 1,737 | 4.2 mi | 56.6 | 37% | 18% |
| Harlech | 1,261 | 4.5 mi | 56 | 34% | 15% |
| Blaenau Ffestiniog | 3,449 | 9.4 mi | 43.4 | 20% | 26% |
| Penygroes | 1,793 | 10.7 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 Porthmadog’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 Porthmadog’s residents
What is the population of Porthmadog?
The 2021 Census counted 2,579 people in Porthmadog’s built-up area.
What is the average age in Porthmadog?
The median age was 48.3 at the 2021 Census, older than 76% of UK towns. 11% of residents were 15 to 24 and 28% were 65 or over.
How diverse is Porthmadog?
94% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 93% across Gwynedd’s towns. 4.9% were born outside the UK.
What religion are people in Porthmadog?
44% said they had no religion and 46% that they were Christian at the 2021 Census; 0.8% were Muslim and 8.9% didn’t answer.
Is Porthmadog good for families?
22% of households had dependent children in 2021, against 27% across Wales’s towns. Schools are on Porthmadog’s schools page.
How many people speak Welsh in Porthmadog?
1,799 residents aged 3 and over, 72%, 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.