Swanley is lived in by working families who stayed put. About six in ten own their homes. A quarter rent from a social landlord. The typical resident is in their late thirties. Students barely register. It is a town of grown-ups with jobs, mortgages and tenancies, and very few people passing through.
Every population figure here comes from the 2021 Census, which counted 17,613 people in 7,108 households in Swanley. About 62% of households own their home, outright or with a mortgage, about 26% rent from a council or housing association and only about 10% rent privately. Social renting is the second-biggest tenure in town, well ahead of private landlords, and with so few private lets the choice for a renter at any one time is short.
The median resident is 39, and about 27% of people are aged 25 to 44. That is a town in its working years, too old to be a student town and too young to be a retirement one, with the school run and the commute setting the rhythm of the week.
The Office for National Statistics models gross household income, before tax, at about £60,000 for the financial year to March 2023, averaged across Swanley's three neighbourhood areas. After tax and housing costs are taken off, the same modelling puts net household income at about £43,000. The gross figure is the one people repeat, and the net figure is closer to the one that decides whether the extension happens.
About 27% of households are one person living alone, and about 14% of all households are a pensioner living alone, a group inside that single-person figure. Couples with dependent children make up about 21% of households, and lone parents about 14%. Swanley has as many lone-parent households as single pensioners, which describes a town where the help that families need and the help that older residents need are both close to home.
About 26% of residents aged 16 and over hold a degree-level qualification, about 23% have no formal qualifications and about 1% are full-time students. The spread runs wide in both directions, and the town's working life is built on trades, services and the warehouses and offices around its road junctions as much as on graduate jobs. Swanley Horticultural College trained students here from 1887 until it merged away to Wye in 1945, and it took most of the student population with it.
Swanley's population profile is below average on the measures that look at deprivation, health and education together, and its deprivation scores slipped between 2019 and 2025, though it remains a stable town of working households who have mostly chosen to stay.