Municipality Hrpelje - Kozina, which is part of the Obalno-kraška statistical region, measures 195 km2; this ranks it 27th among Slovene municipalities.
Statistical data for 2012 reveal the following:
In the middle of 2012 about 4,300 people (about 2,200 men and 2,100 women) were living in the municipality, which ranks Hrpelje - Kozina 116th among Slovene municipalities. The population density was 22 people per square kilometre, which was lower than the national average of 101 people per square kilometre.
The number of live births was higher than the number of deaths, which means that natural increase per 1,000 population in the municipality was positive. It was 0.2 (in Slovenia 1.3). 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 11.7. The sum of natural increase and net migration per 1,000 population in the municipality was positive. It was 11.9 (in Slovenia 1.6).
The mean age of people in Hrpelje - Kozina was 43.4 years, which was higher than the national average (42).
As in most Slovene municipalities, in Hrpelje - Kozina the number of old people was higher than the number of young people: there were 136 people, aged 65 or more, per 100 people aged 0–14. This ratio shows that the value of the ageing index was higher than the national average of 118. It also shows that the mean age of people in Hrpelje - Kozina is growing more rapidly 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 Hrpelje - Kozina – as in most Slovene municipalities – more women were 65+ years old than 14 or less; for men the situation was the same.
Hrpelje - Kozina had 2 kindergartens. They were attended by 135 children or 69% of all children aged 1–5, which was less than the national average of 75%. In the school year 2012/2013 basic schools in Hrpelje - Kozina were attended by about 280 pupils, while various upper secondary schools were attended by about 130 pupils. There were 40 students and 8 graduates per 1,000 people in the municipality; in Slovenia the averages were 47 per 1,000 and 10 per 1,000, respectively.
Among people aged 15–64 (i.e. working age population) about 58% were persons in employment (i.e. persons in paid employment or self-employed persons), which is more than the national average of 57%.
The registered unemployment rate was 10.7%, which is less than the national average (12%). As in most Slovene municipalities, more women than men were unemployed.
In Hrpelje - Kozina, average monthly gross earnings per person employed by legal persons were about 14% lower than the annual average of monthly earnings for Slovenia; and net earnings about 11% lower.
In 2012, there were 532 dwellings per 1,000 population. About 67% of dwellings had at least three rooms. Average size of dwellings in the municipality was 85 m2.
About every other person in Hrpelje - Kozina had a car (59 passenger cars per 100 population); cars in this municipality were on average 9 years old.
In 2012, 304 kg of municipal waste per person was collected in Hrpelje - Kozina, which is 23 kg less than on average in Slovenia.