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 Seaford (SA), accounting for 18.3% (820 people). This share was lower than Onkaparinga (C) (19.2%). Since 2016, the biggest change was in Parents and homebuilders (35 to 49), which increased by 752 people, while its share fell by 3.9 percentage points.
Section overview
Age structure - Service age groups
Seaford (SA) - Total persons (Usual residence)
This table summarises service age groups for Seaford (SA) in 2021 for persons, with comparison against Onkaparinga (C) and change since 2016.
Age structure - Service age groups snapshot
2021 distribution by category for Seaford (SA), with comparison markers for Onkaparinga (C).
Babies and pre-schoolers (0 to 4)
2021 count
214
% of total
4.8%
Change from 2016
+2.5pp
214
4.8%
+2.5pp
Primary schoolers (5 to 11)
2021 count
395
% of total
8.8%
Change from 2016
+3.9pp
395
8.8%
+3.9pp
Secondary schoolers (12 to 17)
2021 count
300
% of total
6.7%
Change from 2016
+0.2pp
300
6.7%
+0.2pp
Tertiary education and independence (18 to 24)
2021 count
302
% of total
6.7%
Change from 2016
-0.2pp
302
6.7%
-0.2pp
Young workforce (25 to 34)
2021 count
506
% of total
11.3%
Change from 2016
+4.8pp
506
11.3%
+4.8pp
Parents and homebuilders (35 to 49)
2021 count
820
% of total
18.3%
Change from 2016
-3.9pp
820
18.3%
-3.9pp
Older workers and pre-retirees (50 to 59)
2021 count
504
% of total
11.2%
Change from 2016
-8.1pp
504
11.2%
-8.1pp
Empty nesters and retirees (60 to 69)
2021 count
574
% of total
12.8%
Change from 2016
-11.7pp
574
12.8%
-11.7pp
Seniors (70 to 84)
2021 count
658
% of total
14.6%
Change from 2016
+6.1pp
658
14.6%
+6.1pp
Elderly aged (85 and over)
2021 count
222
% of total
4.9%
Change from 2016
+4.9pp
222
4.9%
+4.9pp
Chart view
Age structure - Service age groups change
Absolute change in category counts between 2016 and 2021.
Babies and pre-schoolers (0 to 4)
+207
+2.5pp
Primary schoolers (5 to 11)
+380
+3.9pp
Secondary schoolers (12 to 17)
+280
+0.2pp
Tertiary education and independence (18 to 24)
+281
-0.2pp
Young workforce (25 to 34)
+486
+4.8pp
Parents and homebuilders (35 to 49)
+752
-3.9pp
Older workers and pre-retirees (50 to 59)
+445
-8.1pp
Empty nesters and retirees (60 to 69)
+499
-11.7pp
Seniors (70 to 84)
+632
+6.1pp
Elderly aged (85 and over)
+222
+4.9pp
Data table
Service age groups for Seaford (SA). 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) | 214 | 4.8% | 5.4% | 7 | 2.3% | 6.2% | +207 | +2.5pp |
| Primary schoolers (5 to 11) | 395 | 8.8% | 8.6% | 15 | 4.9% | 8.9% | +380 | +3.9pp |
| Secondary schoolers (12 to 17) | 300 | 6.7% | 7.3% | 20 | 6.5% | 7.5% | +280 | +0.2pp |
| Tertiary education and independence (18 to 24) | 302 | 6.7% | 7.9% | 21 | 6.9% | 8.4% | +281 | -0.2pp |
| Young workforce (25 to 34) | 506 | 11.3% | 12.2% | 20 | 6.5% | 12.4% | +486 | +4.8pp |
| Parents and homebuilders (35 to 49) | 820 | 18.3% | 19.2% | 68 | 22.2% | 19.7% | +752 | -3.9pp |
| Older workers and pre-retirees (50 to 59) | 504 | 11.2% | 13.1% | 59 | 19.3% | 13.3% | +445 | -8.1pp |
| Empty nesters and retirees (60 to 69) | 574 | 12.8% | 12.3% | 75 | 24.5% | 12.4% | +499 | -11.7pp |
| Seniors (70 to 84) | 658 | 14.6% | 11.8% | 26 | 8.5% | 9.1% | +632 | +6.1pp |
| Elderly aged (85 and over) | 222 | 4.9% | 2.2% | 0 | 0.0% | 2.1% | +222 | +4.9pp |
| Total | 4,493 | 100.0% | 100.0% | 306 | 100.0% | 100.0% | +4,187 | 0.0pp |