Municipality Železniki, which is part of the Gorenjska statistical region, measures 164 km2; this ranks it 32nd among Slovene municipalities.
Statistical data for 2021 reveal the following:
In the middle of 2021 about 6,680 people (about 3,480 men and 3,210 women) were living in the municipality, which ranks Železniki 80th among Slovene municipalities. The population density was 41 people per square kilometre, which was lower 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 2.8 (in Slovenia -2.0). The number of people who moved from the municipality was higher than the number of people who moved into the municipality, so net migration per 1,000 population in the municipality was negative. It was -6.6. The sum of natural increase and net migration per 1,000 population in the municipality was negative. It was -3.7 (in Slovenia -0.9).
The mean age of people in Železniki was 41.6 years, which was lower than the national average (43.8).
As in most Slovene municipalities, in Železniki the number of old people was higher than the number of young people: there were 105 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 Železniki 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 Železniki – as in most Slovene municipalities – more women were 65+ years old than 14 or less; for men the situation was exactly the opposite.
Železniki had 2 kindergartens, which were attended by 324 children. Of all children in the municipality aged 1–5, 82% were included in kindergartens, which was more than the national average of 81%. In the school year 2021/22 elementary schools in Železniki were attended by about 660 pupils, while various upper secondary schools were attended by about 320 pupils. There were 46 students and 10 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 73% were persons in employment (i.e. persons in paid employment or self-employed persons), which is more than the national average (67%).
In Železniki, average monthly gross earnings per person employed by legal persons were about 6% lower than the annual average of monthly earnings for Slovenia; net earnings were about 4% lower.
Among 1,000 inhabitants in the municipality, 568 had a passenger car. The car was on average 11 years old.
In 2021, 196 kg of municipal waste per person was collected in Železniki, which is 169 kg less than on average in Slovenia.