Municipality Šmartno ob Paki, which is part of the Savinjska statistical region, measures 18 km2; this ranks it 204th among Slovene municipalities.
Statistical data for 2021 reveal the following:
In the middle of 2021 about 3,270 people (about 1,660 men and 1,610 women) were living in the municipality, which ranks Šmartno ob Paki 146th among Slovene municipalities. The population density was 181 people per square kilometre, which was higher than the national average of 104 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 1.8 (in Slovenia -2.0). 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 11.6. The sum of natural increase and net migration per 1,000 population in the municipality was positive. It was 13.4 (in Slovenia -0.9).
The mean age of people in Šmartno ob Paki was 43.1 years, which was lower than the national average (43.8).
As in most Slovene municipalities, in Šmartno ob Paki the number of old people was higher than the number of young people: there were 126 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 139. It also shows that the mean age of people in Šmartno ob Paki is growing more slowly than in Slovenia as a whole. Data by sex show that the ageing index for women was in all municipalities except in five (Črna na Koroškem, Dobrovnik/Dobronak, Jezersko, Loški Potok in Mislinja) higher than the ageing index for men. In Šmartno ob Paki – as in most Slovene municipalities – more women were 65+ years old than 14 or less; for men the situation was the same.
Šmartno ob Paki had 2 kindergartens, which were attended by 155 children. Of all children in the municipality aged 1–5, 87% were included in kindergartens, which was more than the national average of 81%. In the school year 2021/22 elementary school in Šmartno ob Paki was attended by about 340 pupils, while various upper secondary schools were attended by about 140 pupils. There were 34 students and 8 graduates per 1,000 people in the municipality; in Slovenia the averages were 39 per 1,000 and 8 per 1,000, respectively.
Among people aged 15–64 (i.e. working age population) about 67% were persons in employment (i.e. persons in paid employment or self-employed persons), which is the same as the national average.
In Šmartno ob Paki, average monthly gross earnings per person employed by legal persons were about 15% lower than the annual average of monthly earnings for Slovenia; net earnings were about 13% lower.
Among 1,000 inhabitants in the municipality, 599 had a passenger car. The car was on average 11 years old.
In 2021, 268 kg of municipal waste per person was collected in Šmartno ob Paki, which is 97 kg less than on average in Slovenia.