44% of households are couples with children, a share 99% of compared French towns don’t reach
30% of homes are flats in the typical compared French town, against 2.9% in Sercus. At the 2023 Census, 486 people lived in the town, in 180 households. Empty homes: 2.8% of the total. Few places have so few households without a car: 4.2% here, fewer than in 93% of compared French towns.
Throughout this page, the Nord median and the France median are the median of compared communes (those with an overall grade), each figure its own median. Source: INSEE, census 2023.
What stands out about the people of Sercus
A town of families
44% of households are couples with children and 5.7% single parents with children; 26% of residents are under 15. Households ↓
A young town
Half of Sercus’ residents are under 37.1 and half over; the median of compared French towns is 44. 26% are under 15 and 14% are 65 or older. Ages ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
A +15% change since 2012: Sercus grew faster than 81% of compared French towns
Residents at INSEE’s last three censuses, each recast in the 2026 commune boundaries. France has no yearly estimate by commune between censuses.
2012 to 2023
2017 to 2023
Against +5% for the median compared French town and ±0% for the median Nord town, the change came in two steps: +9% from 2012 to 2017, then +5% to 2023.
A median age of 37.1: Sercus is younger than 91% of compared French towns
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Sercus 37.1. The median compared French town: 44.
14% of residents are 65 or over (typical compared French town: 22%). More residents aged 15 to 24 than in 56% of compared French towns: 11%.
Women and men · all residents
49% women, 51% men
About an even split. Median share of women: Nord 51.9%, France 51.8%.
18% of households are one person living alone, fewer than in 99% of compared French towns
A household is everyone who shares a main home (résidence principale). Household types come from INSEE’s fuller sample of a quarter of census forms.
Against the Nord median and the France median
Living alone · share
Households here average 2.8 people each. Fewer single-parent households than in 97% of compared French towns: 5.7%. On average, just over a third of households are one person living alone in the typical compared French town.
Sercus sits below 81% of compared French towns for households in social housing (6.1%)
Every home the census counted: main residences, second homes and occasional dwellings (INSEE counts them together), and empty homes. Owning and renting are on Cost of living.
All homes · share of homes
Type of home
Cars per household · share of households
In the last two years, 7.6% of households moved in; at the other end, 24% have stayed 30 years or more. Against that, 12% of households rent social housing (HLM) in the typical compared French town. 0.6% of homes are second homes, a lower share than in 94% of compared French towns.
A median of €27,200 a year per consumption unit
The standard of living (niveau de vie) is a household’s disposable income after taxes and benefits, divided by its consumption units (UC) to allow for its size and make-up: 1 for the first adult, 0.5 for each other person 14 or older, 0.3 for each child under 14.
Medians of compared communes. Source: INSEE, Filosofi 2023.
At €27,200 a year per consumption unit, the median standard of living here is higher than in 63% of compared French towns.
Below 80% of compared French towns: 5.6% of households are headed by a manager or professional
Households by the socio-professional group (PCS) of their reference person, INSEE’s own categories. Jobs and commuting are on the Work & commute page.
Households by reference person’s group · share of households
Just over one in ten households are headed by a manual worker; in the typical compared French town the figure is 14%. For comparison, nearly one in ten households are headed by a manager or professional in the typical compared French town. The census found that 32% of households are headed by a retired person in Sercus.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
Fewer immigrants than 99% of compared French towns: 0.4%
INSEE publishes two measures, which overlap but aren’t the same. Neither is the UK’s “born abroad”.
Share of residents · census 2023
Immigrant (immigré)
Born abroad, not French at birth. Someone stays an immigrant after becoming French. A French citizen born abroad (for example in Algeria before 1962) is not one.
Foreign national (étranger)
Not a French citizen today, wherever born. A child born in France to foreign parents can be a foreign national without being an immigrant.
INSEE publishes no country of birth or ethnicity by commune in these tables, and the census doesn’t ask about religion.
53% of residents 15 and over are married, a share 97% of compared French towns don’t reach
Residents 15 and over by how they live: the census asks both the legal status and whether people live as a couple.
Residents 15 and over · share
Against a figure of 25% in the typical compared French town, the share of single residents in Sercus comes in at 20%. On average, 43% of residents 15 and over are married in the typical compared French town.
In Sercus, 14% of adults out of school have no qualification, fewer than in 79% of compared French towns
Highest diploma of residents 15 and over who have left education, in French terms: the levels don’t map one-to-one to UK or U.S. ones.
Highest diploma · 15 and over, out of education
Against a figure of 30% in the typical compared French town, the share of graduates of higher education in Sercus comes in at 33%. Elsewhere, 19% of adults out of school have no qualification in the typical compared French town.
The youngest of 41 French towns of 486 to 2,582 people
The 40 compared French towns nearest in population, by median age. Hover for each one’s second homes and immigrants; click for its page.
The youngest is Sercus (37.1), the oldest Prayssac (62.3).
No nearby town is as young as Sercus
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Sercus | 37.1 | 14% | 0.6% | 0.4% |
| Morbecque 2,573 · 3.4 mi | 44.5 | 22% | 1.4% | 1.2% |
| Hazebrouck 21,912 · 3.8 mi | 43.3 | 23% | 1% | 3.1% |
| Aire-sur-la-Lys 9,598 · 5.4 mi | 45.5 | 22% | 0.4% | 1% |
| Isbergues 8,650 · 6.3 mi | 46.1 | 25% | 1.2% | 0.8% |
| Saint-Venant 2,999 · 7 mi | 46.9 | 25% | 1.4% | 2% |
| Arques 9,431 · 7.1 mi | 43.9 | 21% | 1% | 2.8% |
Health, work, housing and schools
What this data can and can’t tell you
- Census 2023. INSEE’s census is a rolling survey: a fifth of small communes each year, 8% of homes in large ones each year. “2023” pools the surveys of 2021 to 2025, so the figures describe the town around 2023, not on one day.
- Medians of compared communes. The comparisons are the median of the département’s compared communes and of France’s (those with an overall grade), each figure its own median: not the total for the département or for France, which large cities pull towards their own figures.
- Immigrants and foreign nationals. INSEE’s two measures: an immigrant was born abroad without French nationality; a foreign national isn’t French today. Neither is a count of people born abroad, which INSEE doesn’t publish by commune.
- Second homes. Homes used for holidays or weekends, with occasional dwellings (kept for work, for example), which INSEE counts together. Their owners are counted where they live, not here.
- Standard of living. INSEE’s Filosofi: disposable income per consumption unit, from tax and benefit files, 2023. The poverty rate is the share of residents below 60% of France’s median. Not published for the smallest communes.
- What France doesn’t ask. The French census asks nothing about ethnicity, religion, language or health, so this page has no such section.
Questions about who lives in Sercus
What is the population of Sercus?
486 at INSEE’s 2023 census, 15% more than in 2012 (423).
How old are Sercus’ residents?
The median age is 37.1, younger than 91% of compared French towns. 32% are under 18 and 14% 65 or older.
How many second homes are there in Sercus?
1, with occasional dwellings: 0.6% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Sercus?
INSEE counts 2 immigrants (born abroad, not French at birth), 0.4% of residents, and 0 foreign nationals (0%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Sercus?
€27,200 a year per consumption unit in 2023 (median of compared French towns €25,970). Source: INSEE, Filosofi.
Sources: INSEE, census 2023 (population, ages, households, homes, marital status, diplomas, immigrants, foreign nationals, employment), 2026 geography · INSEE, Filosofi 2023 (standard of living, poverty) · IGN Admin Express (boundaries) · Medians and percentiles: TownRatings, over compared French towns, updated November 4, 2026. Under the Licence Ouverte / Open Licence 2.0 (Etalab).
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.