Population
Service age groups
About this topic
Service age groups divide the population into broad life-stage bands such as children, young adults, working-age adults, and older people. The groupings are designed to reflect typical demand for age-based services and facilities rather than exact five-year cohorts.
This view is useful for planning childcare, schools, recreation, aged services, and other community infrastructure. It works best alongside five year age groups, household type, and dwelling data, which add more detail about who is living in an area and how needs may change over time.
Interpretation notes
- This is a derived grouping rather than a direct Census question, so the age bands are planning-oriented summaries built from standard age data.
- Percentages relate to the total population; use five year age groups when exact cohort detail matters.
Related topics
Key insight
In 2021, Parents and homebuilders (35 to 49) was the most common category among residents in O'Sullivan Beach, accounting for 18.6% (343 people). This share was lower than Onkaparinga (C) (19.2%). Since 2016, the biggest change was in Seniors (70 to 84), which increased by 80 people and 4.6 percentage points.
Section overview
Age structure - Service age groups
O'Sullivan Beach - Total persons (Usual residence)
This table summarises service age groups for O'Sullivan Beach in 2021 for persons, with comparison against Onkaparinga (C) and change since 2016.
Age structure - Service age groups snapshot
2021 distribution by category for O'Sullivan Beach, with comparison markers for Onkaparinga (C).
Babies and pre-schoolers (0 to 4)
2021 count
78
% of total
4.2%
Change from 2016
-0.4pp
78
4.2%
-0.4pp
Primary schoolers (5 to 11)
2021 count
123
% of total
6.7%
Change from 2016
-1.9pp
123
6.7%
-1.9pp
Secondary schoolers (12 to 17)
2021 count
116
% of total
6.3%
Change from 2016
-0.1pp
116
6.3%
-0.1pp
Tertiary education and independence (18 to 24)
2021 count
118
% of total
6.4%
Change from 2016
-2.0pp
118
6.4%
-2.0pp
Young workforce (25 to 34)
2021 count
235
% of total
12.7%
Change from 2016
-0.2pp
235
12.7%
-0.2pp
Parents and homebuilders (35 to 49)
2021 count
343
% of total
18.6%
Change from 2016
+0.6pp
343
18.6%
+0.6pp
Older workers and pre-retirees (50 to 59)
2021 count
247
% of total
13.4%
Change from 2016
+1.2pp
247
13.4%
+1.2pp
Empty nesters and retirees (60 to 69)
2021 count
244
% of total
13.2%
Change from 2016
-2.8pp
244
13.2%
-2.8pp
Seniors (70 to 84)
2021 count
298
% of total
16.2%
Change from 2016
+4.6pp
298
16.2%
+4.6pp
Elderly aged (85 and over)
2021 count
29
% of total
1.6%
Change from 2016
+0.4pp
29
1.6%
+0.4pp
Chart view
Age structure - Service age groups change
Absolute change in category counts between 2016 and 2021.
Babies and pre-schoolers (0 to 4)
-9
-0.4pp
Primary schoolers (5 to 11)
-38
-1.9pp
Secondary schoolers (12 to 17)
-5
-0.1pp
Tertiary education and independence (18 to 24)
-40
-2.0pp
Young workforce (25 to 34)
-8
-0.2pp
Parents and homebuilders (35 to 49)
+4
+0.6pp
Older workers and pre-retirees (50 to 59)
+18
+1.2pp
Empty nesters and retirees (60 to 69)
-57
-2.8pp
Seniors (70 to 84)
+80
+4.6pp
Elderly aged (85 and over)
+6
+0.4pp
Data table
Service age groups for O'Sullivan Beach. Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Onkaparinga (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Onkaparinga (C)% | Count | % | Onkaparinga (C)% | Count | pp | |
| Babies and pre-schoolers (0 to 4) | 78 | 4.2% | 5.4% | 87 | 4.6% | 6.2% | -9 | -0.4pp |
| Primary schoolers (5 to 11) | 123 | 6.7% | 8.6% | 161 | 8.6% | 8.9% | -38 | -1.9pp |
| Secondary schoolers (12 to 17) | 116 | 6.3% | 7.3% | 121 | 6.4% | 7.5% | -5 | -0.1pp |
| Tertiary education and independence (18 to 24) | 118 | 6.4% | 7.9% | 158 | 8.4% | 8.4% | -40 | -2.0pp |
| Young workforce (25 to 34) | 235 | 12.7% | 12.2% | 243 | 12.9% | 12.4% | -8 | -0.2pp |
| Parents and homebuilders (35 to 49) | 343 | 18.6% | 19.2% | 339 | 18.0% | 19.7% | +4 | +0.6pp |
| Older workers and pre-retirees (50 to 59) | 247 | 13.4% | 13.1% | 229 | 12.2% | 13.3% | +18 | +1.2pp |
| Empty nesters and retirees (60 to 69) | 244 | 13.2% | 12.3% | 301 | 16.0% | 12.4% | -57 | -2.8pp |
| Seniors (70 to 84) | 298 | 16.2% | 11.8% | 218 | 11.6% | 9.1% | +80 | +4.6pp |
| Elderly aged (85 and over) | 29 | 1.6% | 2.2% | 23 | 1.2% | 2.1% | +6 | +0.4pp |
| Total | 1,844 | 100.0% | 100.0% | 1,879 | 100.0% | 100.0% | -35 | 0.0pp |