Municipality Vojnik, which is part of the Savinjska statistical region, measures 75 km2; this ranks it 90th among Slovene municipalities.
Statistical data for 2016 reveal the following:
In the middle of 2016 about 8,740 people (about 4,310 men and 4,430 women) were living in the municipality, which ranks Vojnik 59th among Slovene municipalities. The population density was 116 people per square kilometre, which was higher than the national average 102 people per square kilometre.
The number of live births was lower than the number of deaths, which means that natural increase per 1,000 population in the municipality was negative. It was -3.5 (in Slovenia 0.3). The number of people who moved from the municipality was lower than the number of people who moved into the municipality, so net migration per 1,000 population in the municipality was positive. It was 8.1. The sum of natural increase and net migration per 1,000 population in the municipality was positive. It was 4.6 (in Slovenia 0.8).
The mean age of people in Vojnik was 42.6 years, which was lower than the national average (42.9).
As in most Slovene municipalities, in Vojnik the number of old people was higher than the number of young people: there were 122 people, aged 65 or more, per 100 people aged 0–14. This ratio shows that the value of the ageing index was lower than the national average 125. It also shows that the mean age of people in Vojnik is growing more slowly than in Slovenia as a whole. Data by sex show that the ageing index for women was in all Slovene municipalities higher than the ageing index for men. In Vojnik – in contrast to most Slovene municipalities – more women were 65+ years old than 14 or less; for men the situation was exactly the opposite.
In the school year 2016/2017 basic schools in Vojnik were attended by about 840 pupils, while various upper secondary schools were attended by about 370 pupils. There were 44 students and 17 graduates per 1,000 people in the municipality; in Slovenia the averages were 39 per 1,000 and 15 per 1,000, respectively.
Among people aged 15–64 (i.e. working age population) about 62% were persons in employment (i.e. persons in paid employment or self-employed persons), which is more than national average (60%).
The registered unemployment rate was 10.6%, which is less than the national average (11.2%). As in most Slovene municipalities, more women than men were unemployed.
In Vojnik, average monthly gross earnings per person employed by legal persons were about 16% lower than the annual average of monthly earnings for Slovenia; and net earnings about 14% lower.
In 2015, there were 393 dwellings per 1,000 population. About 67% of dwellings had at least three rooms. Average size of dwellings in the municipality was 84 m2.
Every other person in Vojnik had a car (54 passenger cars per 100 population); cars in this municipality were on average 10 years old.
In 2016, 265 kg of municipal waste per person was collected in Vojnik, which is 82 kg less than on average in Slovenia.