Photo: Jaggery · CC BY-SA 2.0A higher share of residents with no religion than 98% of UK towns, at 55%
Half of Caerphilly’s residents are under 42.1, younger than in just over two thirds of UK towns. The 2021 Census put the town’s population at 33,104, in 14,248 households. On the census count, 29% of households have dependent children. With households in terraced houses at 23%, Caerphilly is ahead of 63% of UK towns on that count.
Caerphilly’s population moved +2% on 2011, less than in 78% of UK towns
ONS mid-year estimates, each year indexed to mid-2011 = 100. Caerphilly’s figure is the small areas (2021 LSOAs) that make up the town.
People, mid-2011 = 100
Change by age, 2011 to 2024
About 31,800 people in 2011; 32,300 in 2024.
Split by age, the 65 and over changed most (+30%) and the 16 to 29 least (−8%). The largest rise in a single year came from mid-2013 to mid-2014: 360 people.
More residents aged 15 to 24 than 71% of UK towns: 10%
Share of residents in each five-year age band, Census 2021.
A fifth of residents are 65 or over, against 21% across Wales’s towns. Against that, 12% of residents are aged 15 to 24 across Wales’s towns. More residents are 50–54 than any other five-year age: 7.1% of residents.
Median age of UK towns of 2,500+
■ Caerphilly, 42.1. The typical town is 44.4.
Broad ages · share of residents
Women and men · all residents
52% women, 48% men
About 94 men for every 100 women. Across Wales, 51% of residents are women.
Residents who moved in within the year make up 6.4% in Caerphilly, less than in 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%.
Across Wales’s towns, 29% of adults are in managerial and professional jobs and 27% in routine work; in Caerphilly, 32% and 25%. For comparison, nearly one in ten residents lived at another address a year earlier across Wales’s towns. 5.9% of adults are full-time students.
The Census was taken on 21 March 2021, in term time, so students were counted at their term addresses.
Below 59% of UK towns: 29% of households are one person living alone
Household make-up at the 2021 Census. Each square is 1% of households.
Against Gwent’s towns and Wales’s towns
People per household
Wales’s towns.
Set against 3.1% across Wales’s towns, 2.1% of households are unrelated adults sharing a home in Caerphilly. Against that, 32% of households are one person living alone across Wales’s towns. Average household size: 2.3 people.
Households without a car or van: 20%, a higher share than 72% 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
Households in detached houses: 23% here and 24% across Wales’s towns. As a yardstick, 21% of households have no car or van across Wales’s towns. The census found that one in ten households live in a flat or apartment in Caerphilly.
Caerphilly sits below 79% of UK towns for residents born outside the UK (3.9%)
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
Where nearly a quarter of those born abroad across Wales’s towns arrived in 2017 or later, here the share is 9%. For residents born outside the UK, the comparison across Wales’s towns is 7.4%. On the census count, 98% of residents have English as their main language.
Of Caerphilly’s residents, 13% can speak Welsh
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
At the 2021 Census, 4,157 residents aged 3 and over, 13%, said they can speak Welsh, against 16% across Welsh towns: more than in 59% of Welsh towns. The highest share in Gwent belongs to Abertridwr and Senghenydd (14%).
A smaller share of residents who describe themselves as Christian than 95% of UK towns: 39%
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 Caerphilly · Gwent’s towns 91% · Wales’s towns 90%.
Religion · all residents
Where 90% of residents describe themselves as White British across Wales’s towns, Caerphilly has 95%. As a reference point, 43% of residents describe themselves as Christian across Wales’s towns. Beyond White British, the biggest groups are Other White (2.1%), Mixed or multiple (1.3%) and Chinese (0.5%).
Caerphilly: 36% of adults have never married or formed a civil partnership, above 70% 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
With married adults and civil partners at 45%, Caerphilly is behind two thirds of UK towns on that count. Typically, 38% of adults have never married or formed a civil partnership across Wales’s towns. The census found that 11% of residents give unpaid care in the town.
Degree-level qualifications reach 29% of adults
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
21% of Caerphilly’s adults have no qualification (20% across Wales’s towns), and 29% have one at degree level (31%).
From a median age of 40 in Llanbradach & Penyrheol to 44 in Caerphilly West
The town’s 4 neighbourhoods (ONS middle-layer areas with 500+ residents inside it, named by the House of Commons Library), youngest first. Census 2021.
Caerphilly West is the oldest area, with 23% aged 65 or over; Llanbradach & Penyrheol the youngest (median age 40). Families with children are most common in Llanbradach & Penyrheol (32% of households).
212 UK towns of 23,000 to 45,000 people: this is the 102nd youngest
Median age, Census 2021. Hover a dot for its students and residents born abroad; click for its page.
Hatfield is the youngest (30.3); Rustington the oldest (56.2). Nearest to Caerphilly in age: Port Talbot (42), Rugeley (42.1), Chorley (42.2) and Chichester (42.2).
Nearby, 3 of 7 towns have older populations than Caerphilly
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 |
|---|---|---|---|---|---|
| Caerphilly | 33,104 | — | 42.1 | 20% | 29% |
| Bedwas | 6,463 | 1.7 mi | 44.4 | 22% | 28% |
| Llanbradach | 3,766 | 2.1 mi | 44.1 | 22% | 25% |
| Abertridwr and Senghenydd | 5,639 | 2.4 mi | 37.6 | 16% | 31% |
| Taff's Well | 3,553 | 2.8 mi | 44.7 | 20% | 25% |
| Trethomas | 1,713 | 2.9 mi | 33.8 | 14% | 38% |
| Tongwynlais | 1,846 | 3.3 mi | 41.8 | 17% | 32% |
| Cwmfelinfach | 1,353 | 3.4 mi | 40.4 | 17% | 27% |
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.
- “Gwent’s towns” and “Wales’s towns” mean their built-up areas. Census comparisons pool every built-up area in Gwent (or Wales), summed the same way as Caerphilly’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. Caerphilly’s trend uses the small areas (2021 LSOAs) with most of their people inside it: 31,965 people in 2021, against 33,104 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 Caerphilly’s residents
What is the population of Caerphilly?
The 2021 Census counted 33,104 people in Caerphilly’s built-up area. The ONS estimates the same small areas held 32,300 people in mid-2024, 2% more than in 2011.
What is the average age in Caerphilly?
The median age was 42.1 at the 2021 Census, younger than 68% of UK towns. 10% of residents were 15 to 24 and 20% were 65 or over.
How diverse is Caerphilly?
95% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 91% across Gwent’s towns. 3.9% were born outside the UK.
What religion are people in Caerphilly?
55% said they had no religion and 39% that they were Christian at the 2021 Census; 0.3% were Muslim and 5.5% didn’t answer.
Is Caerphilly good for families?
29% of households had dependent children in 2021, against 27% across Wales’s towns. Families are most common in Llanbradach & Penyrheol (32% of households). Schools are on Caerphilly’s schools page.
How many people speak Welsh in Caerphilly?
4,157 residents aged 3 and over, 13%, 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.