Zemst: map, population and postcodes

About Zemst

Zemst is a municipality in the province of Flemish Brabant in Flanders, Belgium. On 1 January 2026 it had 23,367 inhabitants on an area of 42.9 km², a population density of 545 inhabitants per km². That is close to the average of 571 per km² in Flemish Brabant and higher than the Belgian average of 387 per km².

By population, Zemst ranks 137th of Belgium’s 565 municipalities and 16th of the 63 municipalities in Flemish Brabant. By area it ranks 281st in Belgium.

The official language is Dutch.

Population of Zemst since 2016

Population on 1 January, 2016–2026. The bars start above zero to make the change visible. Source: Statbel.

Between 1 January 2016 and 1 January 2026 the population of Zemst grew by 299 inhabitants (+1.3%), from 23,068 to 23,367. In the last year it changed by −2. The highest figure in this period was in 2024.

For population growth since 2016, Zemst ranks 465th of 565. Over the same period the province of Flemish Brabant changed by +7.9% and Belgium by +5.3%.