Length of service describes the time between joining the ADF and separation. In this report, length of service is presented in five groups (ranging from less than 1 year to more than 20 years).
The average length of service was just over 10 years with more than one quarter (28%) having between 1 and 5 years of service, while 1 in 5 (20%) had served over 20 years.
Overall, 14% of ex-serving members had served less than 1 year. The proportion was slightly higher for females at 18% compared with males (14%) who had served less than 1 year.
Females generally had a shorter length of service with 1 in 10 (10%) having served over 20 years compared with more than 2 in 10 (22%) of males.
The average length of service was higher for males than females (11 years and 7.8 years respectively).
Table 5: Length of service for ex-serving members, as of 31 December 2019
Length of service (years)(a)
|
Males
(Number)
|
Males
(Per cent)
|
Females
(Number)
|
Females
(Per cent)
|
Persons
(Number)
|
Person
(Per cent)
|
< 1
|
29,821
|
13.6
|
7,210
|
17.5
|
37,031
|
14.2
|
1 – <5
|
59,020
|
26.9
|
13,230
|
32.1
|
72,250
|
27.7
|
5 – <10
|
40,400
|
18.4
|
8,772
|
21.3
|
49,172
|
18.9
|
10 – <20
|
41,252
|
18.8
|
7,743
|
18.8
|
48,995
|
18.8
|
20 or more
|
47,802
|
21.8
|
4,066
|
9.9
|
51,868
|
19.9
|
Total ex-serving(b)
|
219,411
|
100.0
|
41,213
|
100.0
|
260,624
|
100.0
|
Mean length of service (years)
|
10.9
|
. .
|
7.8
|
. .
|
10.4
|
. .
|
. . not applicable.
(a) The time between the date of hire and date of separation from the ADF.
(b) Sum of component items do not equal totals. For 1,116 ex-serving males and 192 ex-serving females, length of service was unable to be calculated due to not having a hire date for these records.
Source: AIHW analysis of linked Defence Historical Personnel data–PMKeyS–NDI data, 1985–2019.
As expected, as a person’s age increases so does the average length of service. Nearly half (47%) of members with over 20 years of service were aged 65 years and over. Older males (over the age of 55) have a longer average length of service than their female counterparts while younger males and females have a similar average length of service.

Source: AIHW analysis of linked Defence Historical Personnel data–PMKeyS–NDI data 1985–2019.