Dwelling Density Calculator
Net dwelling density and population density for a site from its area, lot size or dwelling count, and household size — with the housing typology that density implies.
Net density is dwellings per hectare of residential land after roads and open space are taken out.
How the dwelling density calculator works
Net density is dwellings per hectare of residential land after roads and open space are taken out. From a lot size, the count is site area × the share that is actually lots ÷ lot area; from a known count, just divide. Multiply by persons per dwelling for population density. Detached houses sit at 10–20 dwellings per hectare, townhouses 25–45, low-rise apartments 60–100, towers 150 and up.
Formula: dwellings = site × net share ÷ lot area; density = dwellings ÷ (site × net share)
Worked examples
| Inputs | Net dwelling density | Note |
|---|---|---|
| 10 ha at 70% net, 450 m² lots | 22.1 dwellings/ha | 155 dwellings; 22.1 per net ha |
| 2 ha apartment site with 240 dwellings | 120 dwellings/ha | 120 per ha — mid-rise |
| Townhouses on 200 m² lots | 49.8 dwellings/ha | 162 dwellings; 50 per net ha |
FAQFrequently asked questions
Net or gross density?
Net counts only residential land and is what zoning controls; gross includes roads, parks and shops and is what a whole suburb measures. Gross is typically 60–75% of net for a subdivision; the calculator shows both.
What density supports public transport?
Frequent bus service is usually viable above about 30–35 dwellings per hectare gross, rail above 50–60. Below 15 most trips will be by car whatever the service.
How does lot size map to density?
A 450 m² lot at 70% net is about 15.5 dwellings per hectare; 300 m² lots about 23; 200 m² townhouse lots about 35. Apartments break the link because dwellings stack.
What household size should I use?
National averages run 2.3–2.6 persons per dwelling; apartments in inner areas are nearer 1.8, family suburbs 3 or more. Use the local census figure for the housing type.
Where these figures come from
- UN-Habitat — Urban Indicators Guidelines — density, green space and public space benchmarks
- World Health Organization — Urban green spaces — the 9 m² per person minimum
- ITE — Parking Generation Manual — parking demand rates by land use
- Office for National Statistics — Population estimates — the UK's national statistics agency
Last checked: September 2026. Default per-capita rates are mid-range figures from national statistical agencies and utility reports; every one is an input you should replace with the local figure.