---
title: "share of population under 18 years old with foreign background or non-Belgian citizenship in the Brussels-Capital Region"
analysis_id: "LktsuTHGXD0u2hFtqr8i"
model: accounts/fireworks/models/deepseek-v4p1-flash
success: true
---

# Data analysis: share of population under 18 years old with foreign background or non-Belgian citizenship in the Brussels-Capital Region

Model: DeepSeek V4.1 Flash
Checked on: 10/10/2026

## Findings

##### Brussels-Capital Region (BE10) — young population by citizenship / origin

Using **Eurostat's 2021 Census** tables for the Brussels-Capital Region (NUTS‑2 = BE10)[^1][^2], complemented by the single‑year age totals[^3]:

**Total population 2021:** 1,226,329, of which **277,043 are under 18**.

| Age group | Total | Non-Belgian citizenship | Foreign-born (proxy for foreign background) |
| --- | --- | --- | --- |
| 0–4 | 80,361 | 23.1% | 6.4% |
| 5–9 | 79,938 | 29.7% | 15.3% |
| 10–14 | 75,739 | 26.5% | 21.4% |
| **Under 15** | 236,038 | **26.4%** | **14.2%** |
| 15–19 | 68,256 | 26.9% | 27.6% |
| All ages | 1,226,329 | 35.0% | 46.4% |

**Answer:**

- **Non-Belgian citizenship:** about **26–27%** of the under‑18 population. The census publishes the exact band only down to *under 15* (26.4% ≈ 62,300 children) and the *15–19* band (26.9%); combining these with the single‑year age totals gives an **estimated under‑18 figure of ≈26.5% (≈73,400 of 277,000)**.
- **Foreign background:** this is a Belgian‑specific concept (based on nationality at birth / parents' origin) that **is not produced in the Eurostat/OECD datasets**. The closest available measure — *foreign‑born* (born outside Belgium) — is **14.2% of under‑15s and ≈16% of under‑18s**. This is only a **partial proxy and clearly understates "foreign background"**, because many children of foreign parents are themselves born in Belgium (note how the foreign‑born share rises sharply with age, from 6% at 0–4 to 28% at 15–19).

A comparison chart was produced in  (`brussels_young_origin.svg`).

**Caveats:** The regional census tables do not publish an exact "under‑18" breakdown by citizenship/origin, so the under‑18 citizenship figure is an estimate (the two adjacent published bands, under‑15 and 15–19, both sit near 26.5%, so the estimate is robust). The OECD's *"Population by citizenship – Cities and FUAs"* dataset would contain an exact under‑18 citizenship/origin breakdown for Brussels, but its dataflow was unavailable (persistent server‑side error), so it could not be used.

[^1]:
    [Eurostat dataset: Population by groups of country of citizenship, age groups, groups of current activity status and NUTS 2 region](https://ec.europa.eu/eurostat/databrowser/view/cens_21ctza_r2/default/table)

[^2]:
    [Eurostat dataset: Population by groups of country of birth, age groups, groups of current activity status and NUTS 2 region](https://ec.europa.eu/eurostat/databrowser/view/cens_21coba_r2/default/table)

[^3]:
    [Eurostat dataset: Population by age and NUTS 2 region](https://ec.europa.eu/eurostat/databrowser/view/cens_21agr2/default/table)