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 Hornsby (A), accounting for 22.2% (33,637 people). This share was higher than Greater Sydney (21.5%). Since 2016, the biggest change was in Seniors (70 to 84), which increased by 3,202 people and 1.6 percentage points.
Section overview
Age structure - Service age groups
Hornsby (A) - Total persons (Usual residence)
This table summarises service age groups for Hornsby (A) in 2021 for persons, with comparison against Greater Sydney and change since 2016.
Chart view
Age structure - Service age groups snapshot
2021 distribution by category for Hornsby (A), with comparison markers for Greater Sydney.
Babies and pre-schoolers (0 to 4)
2021 count
7,614
% of total
5.0%
Change from 2016
-0.8pp
7,614
5.0%
-0.8pp
Primary schoolers (5 to 11)
2021 count
14,726
% of total
9.7%
Change from 2016
0.0pp
14,726
9.7%
0.0pp
Secondary schoolers (12 to 17)
2021 count
12,581
% of total
8.3%
Change from 2016
+0.1pp
12,581
8.3%
+0.1pp
Tertiary education and independence (18 to 24)
2021 count
12,061
% of total
7.9%
Change from 2016
-0.6pp
12,061
7.9%
-0.6pp
Young workforce (25 to 34)
2021 count
14,391
% of total
9.5%
Change from 2016
-0.8pp
14,391
9.5%
-0.8pp
Parents and homebuilders (35 to 49)
2021 count
33,637
% of total
22.2%
Change from 2016
+0.1pp
33,637
22.2%
+0.1pp
Older workers and pre-retirees (50 to 59)
2021 count
20,432
% of total
13.5%
Change from 2016
-0.3pp
20,432
13.5%
-0.3pp
Empty nesters and retirees (60 to 69)
2021 count
16,513
% of total
10.9%
Change from 2016
+0.6pp
16,513
10.9%
+0.6pp
Seniors (70 to 84)
2021 count
15,534
% of total
10.2%
Change from 2016
+1.6pp
15,534
10.2%
+1.6pp
Elderly aged (85 and over)
2021 count
4,319
% of total
2.8%
Change from 2016
+0.1pp
4,319
2.8%
+0.1pp
Age structure - Service age groups change
Absolute change in category counts between 2016 and 2021.
Babies and pre-schoolers (0 to 4)
-670
-0.8pp
Primary schoolers (5 to 11)
+887
0.0pp
Secondary schoolers (12 to 17)
+873
+0.1pp
Tertiary education and independence (18 to 24)
-34
-0.6pp
Young workforce (25 to 34)
-300
-0.8pp
Parents and homebuilders (35 to 49)
+2,138
+0.1pp
Older workers and pre-retirees (50 to 59)
+786
-0.3pp
Empty nesters and retirees (60 to 69)
+1,787
+0.6pp
Seniors (70 to 84)
+3,202
+1.6pp
Elderly aged (85 and over)
+486
+0.1pp
Data table
Service age groups for Hornsby (A). Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Greater Sydney.
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Greater Sydney% | Count | % | Greater Sydney% | Count | pp | |
| Babies and pre-schoolers (0 to 4) | 7,614 | 5.0% | 6.0% | 8,284 | 5.8% | 6.4% | -670 | -0.8pp |
| Primary schoolers (5 to 11) | 14,726 | 9.7% | 8.8% | 13,839 | 9.7% | 8.8% | +887 | 0.0pp |
| Secondary schoolers (12 to 17) | 12,581 | 8.3% | 7.1% | 11,708 | 8.2% | 6.9% | +873 | +0.1pp |
| Tertiary education and independence (18 to 24) | 12,061 | 7.9% | 8.8% | 12,095 | 8.5% | 9.6% | -34 | -0.6pp |
| Young workforce (25 to 34) | 14,391 | 9.5% | 15.5% | 14,691 | 10.3% | 16.1% | -300 | -0.8pp |
| Parents and homebuilders (35 to 49) | 33,637 | 22.2% | 21.5% | 31,499 | 22.1% | 21.1% | +2,138 | +0.1pp |
| Older workers and pre-retirees (50 to 59) | 20,432 | 13.5% | 12.0% | 19,646 | 13.8% | 12.2% | +786 | -0.3pp |
| Empty nesters and retirees (60 to 69) | 16,513 | 10.9% | 9.8% | 14,726 | 10.3% | 9.5% | +1,787 | +0.6pp |
| Seniors (70 to 84) | 15,534 | 10.2% | 8.7% | 12,332 | 8.6% | 7.5% | +3,202 | +1.6pp |
| Elderly aged (85 and over) | 4,319 | 2.8% | 2.0% | 3,833 | 2.7% | 2.0% | +486 | +0.1pp |
| Total | 151,811 | 100.0% | 100.0% | 142,667 | 100.0% | 100.0% | +9,144 | 0.0pp |