The average age of the population is the arithmetic mean of the exact ages of the total population on 1 January 2021.
The average age of the whole population living in Belgium is just under 42 years old. It was just under 41 years old in 2011. These figures vary from region to region. The average age in the Brussels-Capital Region remains stable at 37.7 years old (37.6 years old in 2011), making it the youngest region. In the other two regions, the average age rises from 40.4 years old in 2011 to 41.7 in 2021 in Wallonia and from 41.7 to 43 in Flanders.
The highest average ages by municipality are observed on the coast, in the area between Antwerp and Liège and in some scattered municipalities such as Vresse-sur-Semois, Horebeke, Sint-Martens-Latem and Chaudfontaine (average age between 46 and 49 years old).
The lowest average ages can be found in Antwerp, the north-west of the Brussels-Capital Region, the block formed by the south-east of Walloon Brabant, the west of the province of Liège and the north of the province of Namur and all the south-east of Luxembourg.
The relative importance of the population under 15 is measured as the ratio between this population and the total population.
Nearly 17% of the population living in Belgium is under 15 years old. This figure is the lowest in Flanders (16%) and the highest in the Brussels-Capital Region (19%), with Wallonia in between (17%).
At municipal level, the highest percentages are mainly concentrated in some municipalities in the west of the Brussels-Capital Region and in the centre of the province of Luxembourg.
Conversely, the municipalities on the coast and some other scattered municipalities (Vresse-sur-Semois, Ixelles, Gerpinnes and Grobbendonk) have the lowest figures. In Koksijde, for example, less than 1 inhabitant out of 10 is under 15 years old.
The relative importance of the population between 15 and 64 years old is measured as the ratio between this population and the total population.
In Belgium, two thirds of the population are between 15 and 64 years old. While it is slightly higher in the Brussels-Capital Region (68%), this percentage is similar in Flanders and in Wallonia (63% and 64% respectively).
The highest percentages can be found in the municipalities in the centre of the capital, in the urban agglomerations of the country and in municipalities scattered mainly in Wallonia. The lowest percentages can be observed on the coast and in some municipalities in the south of the country, close to the Semois.
The relative importance of the population aged 65 and over is measured as the ratio between this population and the total population.
While the share of the population aged 65 and over was equal to the share of the population under 15 in 2011 (17.2%), it amounts to 19.4% in 2021.
The Brussels-Capital Region has the lowest percentage of people aged 65 and over (13%) and Flanders has the highest percentage (21%), Wallonia is in between (19%).
The highest percentages are observed in the coastal municipalities and the lowest in the Brussels-Capital Region. We also note the contrast in the Brussels-Capital Region between the south-eastern municipalities where the population aged 65 and over is significant and the northern municipalities where it is lower.
The old-age dependency ratio is defined as the ratio between the number of persons aged 65 and over and the number of persons aged 15 to 64.
The old-age dependency ratio amounted to 26% in Belgium in 2011. It increased to 30% in 2021, which illustrates the ageing of the population. It is only 19% in the Brussels-Capital Region (20% in 2011), but it increased to 30% in Wallonia (25% in 2011) and even to 33% in Flanders (27% in 2011).
The highest rates (30% and more) are observed in West Flanders (particularly on the coast), in East Flanders, around Antwerp and Mechelen, in eastern Flemish Brabant and in municipalities crossed by the Semois along the French border. The centre of the Brussels-Capital Region has the lowest percentages.
The Census 2021 in a nutshell
The Census 2021 is a snapshot of the population living in Belgium on 1 January 2021. It provides a wide range of figures on housing and demographic, socio-economic and educational characteristics of the citizens. The objective of the Census is twofold: to comply with the European regulation[1] and to produce statistics to address national specific needs (public services, international organizations, researchers, enterprises and private individuals).
Previously based on an exhaustive survey of all citizens, since 2011 the Census has been based exclusively on the use of administrative databases.
Definitions
The various statistical units
Population
The population taken into account for the Census 2021 is the residential population, as registered in the National Register of Natural Persons (RNPP) on 1 January 2021. The Belgian population includes Belgians and non-Belgians who have been allowed or authorised to settle or to stay in Belgium but does not include non-Belgians living on the territory for less than three months, asylum seekers and non-Belgians in an illegal situation[2].
Private households
This group includes people living alone in a dwelling and groups of several people living in the same dwelling and providing themselves with essentials for living.
Family nuclei
A family nucleus is defined as two or more persons who belong to the same household and who are related as husband and wife, as partners in a registered partnership, as partners in a consensual union, or as parent and child.
Living quarters
Living quarters refer to all quarters used as the usual residence of one or several persons.
Conventional dwellings
Conventional dwellings are separate units (surrounded by walls and covered by a roof) that are independent (with a direct access from the street or a staircase, passage) and designed to be used as a permanent dwelling.
Occupied conventional dwellings
Occupied conventional dwellings are conventional dwellings used as the usual residence of one or several private households.
Variables and their description
Sex
This variable is used to distinguish men from women.
Age
The age reached in completed years of age on 1 January 2021.
Place of usual residence
The place of residence is that registered in the National Register on 1 January 2021. So this is the place of legal residence.
The Belgian municipalities have changed between 2011 and 2021. In the comparisons shown on this website, the figures for 2011 are broken down according to the municipalities of 2021.
Locality
A locality is defined as a distinct population cluster, that is an area defined by population living in neighbouring or contiguous buildings. This area constitutes a group of buildings, none of which is separated from its nearest neighbour by more than 200 meters.
The Belgian municipalities have changed between 2011 and 2021. In the comparisons shown on this website, the figures for 2011 are broken down according to the municipalities of 2021.
Remark
The comparison with the previous Census requires some caution: this publication is based on the Belgian population and the Census 2011 has as reference the European definition of the population.
Information on the difference between the Belgian population and the Census 2011 population.
[1] COMMISSION IMPLEMENTING REGULATION (EU) 2017/543 of 22 March 2017 laying down rules for the application of Regulation (EC) No 763/2008 of the European Parliament and of the Council on population and housing censuses as regards the technical specifications of the topics and of their breakdowns.
[2]Information on the difference between the Belgian population and the Census 2011 population.