Duncan Postcode
South Australia
Income, rent and SEIFA figures are from the ABS 2021 Census and are reported in 2021 dollars, not adjusted for subsequent inflation.
How Duncan Compares
Duncan vs the SA average and the national average (2021 Census, population-weighted).
| Metric | Duncan | SA avg | AU avg |
|---|---|---|---|
| Household income/wk | $1,875 +SA | $1,545 | $1,836 |
| Rent/wk | $158 -SA | $308 | $390 |
| Mortgage/month | $550 -SA | $1,558 | $1,958 |
| Median age | 32 | 45.0 | 45.0 |
| SEIFA decile | 6/10 ≈SA | 5.0/10 | 6.0/10 |
| Unemployment | 0.0% -SA | 6.0% | 5.0% |
Green pill = at least 10% above the SA average; red = at least 10% below; grey = within 10%. For unemployment, colour polarity is inverted: lower is better.
Duncan is a remote community in South Australia, with postcode 5223. It lies roughly 161 km from Adelaide, classified by the ABS as remote Australia. The area is administered by Kangaroo Island.
According to the 2021 Census, Duncan has a population of 67 with a median age of 32. The median weekly household income is $1,875, above the SA average.
Housing in Duncan includes a median weekly rent of $158, median monthly mortgage repayment of $550, with 21 total dwellings. Housing costs in the area sit below the SA average. Owner-occupied dwellings (owned or mortgaged) make up 77.8% of housing.
On the SEIFA Index of Relative Socio-economic Advantage and Disadvantage, Duncan scores in decile 6 out of 10, which is around the national average.
Duncan is part of the Fleurieu - Kangaroo Island statistical area in South Australia.
Duncan Details
| Postcode | 5223 |
| State | South Australia (SA) |
| Phone Area Code | 08 |
| Population (2021) | 67 |
| Median Age | 32 years |
| Median Household Income (Census 2021) | $1,875/week |
| Median Personal Income (Census 2021) | $1,017/week |
| Median Weekly Rent (Census 2021) | $158 |
| Median Monthly Mortgage (Census 2021) | $550 |
| Average Household Size | 2.5 persons |
| Area | 173.6 km² |
| Population Density | 0/km² |
| Total Dwellings | 21 |
| Australian Citizens | 80.6% |
| Unemployment Rate | 0.0% |
| SEIFA IRSAD Decile | 6/10 (average) |
| Latitude | -35.7342193 |
| Longitude | 137.1204416 |
| Distance from Adelaide | 161 km |
| Region (SA4) | South Australia - South East |
| Area (SA3) | Fleurieu - Kangaroo Island |
| Local Government | Kangaroo Island |
| Federal Electorate | Mayo |
Age Profile
Show counts
| 0–14 years | 19 (28.4%) |
| 15–24 years | 6 (9.0%) |
| 25–44 years | 26 (38.8%) |
| 45–64 years | 13 (19.4%) |
| 65+ years | 8 (11.9%) |
Housing Tenure
SEIFA Socio-economic Index
Index of Relative Socio-economic Advantage and Disadvantage (IRSAD), decile 6 of 10. Higher deciles indicate more advantage.
Health Conditions (2021 Census)
| Asthma | 8 (11.9%) |
Long-term health conditions self-reported in the 2021 Census. Persons may report more than one condition.
Motor Vehicles per Dwelling
| No vehicle | 0 (0.0%) |
| 1 vehicle | 3 (12.0%) |
| 2 vehicles | 9 (36.0%) |
| 3+ vehicles | 13 (52.0%) |
Suburbs Near Duncan
Same Postcode (5223)
More Duncan Data
Page last reviewed . Data sources: Australian Bureau of Statistics 2021 Census (CC BY 4.0), SEIFA 2021 IRSAD, ACARA school profiles 2025. How this data is sourced.