Municipality Celje, which is part of the savinjska statistical region, measures 95 km2; this ranks it 75th among Slovene municipalities.
Statistical data for 2015 reveal the following:
In the middle of 2015 about 48,900 people (about 24,200 men and 24,700 women) were living in the municipality, which ranks Celje 5th among Slovene municipalities. The population density was 515 people per square kilometre, which was higher than the national average of 102 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 1.4 (in Slovenia 0.4). 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 4.6. The sum of natural increase and net migration per 1,000 population in the municipality was positive. It was 6.1 (in Slovenia 0.6).
The mean age of people in Celje was 43.4 years, which was higher than the national average (42.6).
As in most Slovene municipalities, in Celje the number of old people was higher than the number of young people: there were 132 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 123. It also shows that the mean age of people in Cerklje na Gorenjskem 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 Celje – as in most Slovene municipalities – more women were 65+ years old than 14 or less; for men the situation was the same.
In the school year 2015/2016 basic schools in Celje were attended by about 3,750 pupils, while various upper secondary schools were attended by about 1650 pupils. There were 40 students and 9 graduates per 1,000 people in the municipality; in Slovenia the averages were 39 per 1,000 and 9 per 1,000, respectively.
Among people aged 15–64 (i.e. working age population) about 57% were persons in employment (i.e. persons in paid employment or self–employed persons), which is less than the national average (58%).
The registered unemployment rate was 16.1%, which is more than the national average (12.3%). As in most Slovene municipalities, more women than men were unemployed.
In Celje, average monthly gross earnings per person employed by legal persons were about 3% lower than the annual average of monthly earnings for Slovenia; and net earnings about 20% higher.
In 2015, there were 430 dwellings per 1,000 population. About 51% of dwellings had at least three rooms. Average size of dwellings in the municipality was 69 m2.
Every other person in Celje had a car (50 passenger cars per 100 population); cars in this municipality were on average 9.4 years old.
In 2015, 424 kg of municipal waste per person was collected in Celje, which is 109 kg more than on average in Slovenia.