In Le Pecq, 31% of households are headed by a manager or professional, more than in 97% of compared French towns
The figure for flats is 81% in Le Pecq and 30% in the typical compared French town. In 2023, the Census found 16,059 residents locally, living in 6,900 households. 16% of households have no car, or about one in six. Couples with children are more common here than in 78% of compared French towns.
Throughout this page, the Yvelines 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 Le Pecq
Many graduates
59% of residents 15 and over who have left education hold a diploma above the bac, 32% a master’s or more (bac+5). Qualifications ↓
Immigrants
INSEE counts 2,700 immigrants in Le Pecq (people born abroad who weren’t French at birth, whatever their nationality now): 17% of residents, against 15% for the median compared commune in Yvelines. 11% are foreign nationals. Immigrants and foreign nationals ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
Le Pecq’s population moved −2% on 2012, less than in 77% 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
Medians for comparison: +5% across compared French towns, +7% in Yvelines.
A lower share of residents aged 65 and over than 70% of compared French towns, at 19%
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Le Pecq 42.5. The median compared French town: 44.
The median age in Le Pecq is 42.5, lower than in 62% of compared French towns. Put another way, about one in eight: 12% of residents are 15 to 24. Typically, 22% of residents are 65 or over in the typical compared French town.
Women and men · all residents
53% women, 47% men
About 88 men for every 100 women. Median share of women: Yvelines 51.6%, France 51.8%.
Le Pecq ranks above 76% of compared French towns on single-parent households: 12%
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 Yvelines median and the France median
Living alone · share
Households average 2.3 people. Compared with other places, one-person households are common here: 36%, more than in 53% of compared French towns. In the typical compared French town, 10% of households are single parents.
Le Pecq ranks above 61% of compared French towns on households in social housing: 15%
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
One household in six has no car, against 11% in the median compared French town. For households in social housing, the comparison in the typical compared French town is 12%. Second homes account for 1.1%. On empty homes, Le Pecq sits higher than 65% of compared French towns: 8.1%.
Per consumption unit, the median standard of living is €35,280 a year
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.
Per consumption unit, half of residents live on more than €35,280 a year: higher than in 96% of compared French towns. 10.0% of residents have a standard of living below 60% of France’s median.
5.3% of households are headed by a manual worker, fewer than in 96% of compared French towns
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
Households headed by a retired person: 27% here and 32% in the typical compared French town. The usual figure: 14% of households are headed by a manual worker in the typical compared French town.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
Immigrants make up 17% in Le Pecq, more than in 88% of compared French towns
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.
The median compared commune in Yvelines has 15%; immigrants here make up a share higher than in 88% of compared French towns. The benchmark for immigrants in the typical compared French town: 6.5%. Foreign nationals come to 11% in Le Pecq, about one in ten.
INSEE publishes no country of birth or ethnicity by commune in these tables, and the census doesn’t ask about religion.
Single residents: 29%, a higher share than 76% of compared French towns
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
At 44%, the share of married residents is higher than in 54% of compared French towns. Typically, 25% of residents 15 and over are single in the typical compared French town.
Le Pecq: 59% of adults out of school hold a higher-education qualification, above 97% 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
Set against 19% in the typical compared French town, nearly one in ten adults out of school have no qualification in Le Pecq. The wider picture: 30% of adults out of school hold a higher-education qualification in the typical compared French town.
Ranked by age, 16th oldest of 41 French towns this size
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 Montévrain (32.8), the oldest Biscarrosse (53.2).
Le Pecq is younger than 4 of its 6 nearest neighbors
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Le Pecq | 42.5 | 19% | 1.1% | 17% |
| Le Port-Marly 5,559 · 1 mi | 37.4 | 15% | 3% | 24% |
| Saint-Germain-en-Laye 45,931 · 1.1 mi | 41.3 | 18% | 4.2% | 19% |
| Le Vésinet 15,554 · 1.2 mi | 44.5 | 21% | 1.8% | 14% |
| Marly-le-Roi 16,756 · 1.3 mi | 44.3 | 21% | 1.7% | 13% |
| Mareil-Marly 4,141 · 1.4 mi | 43.2 | 16% | 3.1% | 15% |
| Croissy-sur-Seine 11,013 · 1.9 mi | 43.2 | 19% | 1.6% | 15% |
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 Le Pecq
What is the population of Le Pecq?
16,059 at INSEE’s 2023 census, 2% fewer than in 2012 (16,350).
How old are Le Pecq’s residents?
The median age is 42.5, younger than 62% of compared French towns. 24% are under 18 and 19% 65 or older.
How many second homes are there in Le Pecq?
86, with occasional dwellings: 1.1% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Le Pecq?
INSEE counts 2,690 immigrants (born abroad, not French at birth), 17% of residents, and 1,770 foreign nationals (11%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Le Pecq?
€35,280 a year per consumption unit in 2023 (median of compared French towns €25,970); 10.0% of residents live below the poverty line. 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 8, 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.