Municipality Mirna Peč, which is part of the Jugovzhodna Slovenija statistical region, measures 48 km2; this ranks it 137th among Slovene municipalities.
Statistical data for 2011 reveal the following:
In the middle of 2011 about 2,800 people (about 1,400 men and 1,400 women) were living in the municipality, which ranks Mirna Peč 160th among Slovene municipalities. The population density was 59 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 4.6 (in Slovenia 1.6). 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 6.7. The sum of natural increase and net migration per 1,000 population in the municipality was positive. It was 11.4 (in Slovenia 2.6).
The mean age of people in Mirna Peč was 39.1 years, which was lower than the national average (41.8).
In contrast to most Slovene municipalities, in Mirna Peč the number of young people was higher than the number of old people: there were 80 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 of 117. It also shows that the mean age of people in Mirna Peč 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 Mirna Peč – in contrast to most Slovene municipalities – fewer women were 65+ years old than 14 or less; for men the situation was the same.
Mirna Peč had 1 kindergarten. It was attended by 132 children or 77% of all children aged 1–5, which was more than the national average of 76%. In the school year 2011/2012 basic school in Mirna Peč was attended by about 250 pupils, while various upper secondary schools were attended by about 140 pupils. There were 60 students and 13 graduates per 1,000 people in the municipality; in Slovenia the averages were 51 per 1,000 and 10 per 1,000, respectively.
Among people aged 15–64 (i.e. working age population) about 63% were persons in employment (i.e. persons in paid employment or self-employed persons), which is more than the national average of 58%.
The registered unemployment rate was 8.3%, which is less than the national average (11.8%). In contrast to most Slovene municipalities, more men than women were unemployed.
In Mirna Peč, average monthly gross earnings per person employed by legal persons were about 7% lower than the annual average of monthly earnings for Slovenia; and net earnings about 4% lower.
Every 45th person in the municipality was receiving at least one financial social assistance. In Slovenia as a whole every 24th person received at least one financial social assistance.
In 2011, there were 401 dwellings per 1,000 population. About 64% of dwellings had at least three rooms. Average size of dwellings in the municipality was 82 m2.
About every other person in Mirna Peč had a car (54 passenger cars per 100 population); cars in this municipality were on average 8 years old.
In 2011, 220 kg of municipal waste per person was collected in Mirna Peč, which is 132 kg less than on average in Slovenia.