Belgium's 5 % electoral threshold: how to calculate it

Belgium's electoral threshold is 5 % of valid votes, but it is measured in each constituency (circonscription), never across the whole country. In 2024, Groen collected 4.65 % of the vote nationally and still sent six members to the Chamber of Representatives.

The national figure, the one shown on screens on election night, therefore says nothing about whether the threshold was cleared.

Does the 5 % threshold apply to the whole country?

No, and the 9 June 2024 election offers four illustrations. The figures come from the Chamber's results sheet.

DéFI only reached 1.20 % across the country. In Brussels, where its votes are concentrated, the list weighed 6.58 % and was therefore admitted to the seat allocation.

What exactly does the rule say?

Article 165bis of the Electoral Code reserves the seat allocation for lists that reach the bar. The record each main constituency office completes repeats the wording: "Only lists that obtained at least 5 % of the overall total are admitted to the seat allocation" (Home Affairs form A/24, 26 May 2019 election, original in French).

It dates from the law of 13 December 2002 and was first used on 18 May 2003 (parliamentary document 51 0251/001).

How do you calculate the threshold in your constituency?

The calculation takes two minutes, a calculator and the official record.

1. Find the constituency's total valid votes. Blank and invalid votes are not part of it.
2. Multiply that total by 0.05.
3. Compare the result with the list's number of votes.
4. If the list is above, it enters the allocation under the D'Hondt method. If not, it drops out, and its votes go to nobody else.

Example in the province of Luxembourg, in 2024. Les Engagés won 56,289 votes there, or 32.09 %, which puts the total of valid votes at around 175,400. Five per cent of 175,400 is about 8,770 votes. That is the bar.

How many votes are needed in each constituency?

Far more in Antwerp than in Arlon. The table below rebuilds the bar in votes for six of the Chamber's eleven constituencies, from the percentages and totals published for 2024. These are rounded orders of magnitude, calculated for this article.

The same 5 % therefore demands nearly seven times as many votes in Antwerp as in the province of Luxembourg.

Does the threshold shut out many voters?

Fewer than you might think, and its exact share is hard to isolate. The thirteen lists that won no seat at the 2024 federal election total about 299,000 votes, or 4.3 % of the country's valid votes, according to the results reproduced by Wikipedia. But those lists did not all fail because of the 5 % bar. In many constituencies the arithmetic of the allocation is already harsher than the law: that is the case in nine constituencies out of eleven, as our article on the D'Hondt method explains.

Three mistakes come back every election night:

• reading the national percentage as if it decided the seats;
• believing that the votes of a list below the bar are redistributed to the others;
• confusing the total of valid votes with the number of ballots cast.

Where does the threshold apply outside the Chamber?

The rules vary from one assembly to another. The table reflects the position described by RTBF at the 2019 election, which should be checked against the Electoral Code before any decision.

Source: RTBF, 2019, in French. The same article describes, for the Walloon and Brussels parliaments, a grouping of lists that lets small lists count together. At the 2014 regional election in Brussels, a group uniting the PTB (PVDA in Dutch) and four other lists totalled 5.5 % and won four seats, all of them awarded to the PTB, which stood at 3.6 % on its own.

Why have a threshold? The arguments on each side

For its defenders, the rule limits the number of groups in assemblies. During the January 2004 debate on a special law on electoral matters, MP Josy Arens (cdH, a centrist party now called Les Engagés) argued that the threshold avoids excessive fragmentation of the political landscape (document 51 0584/004). On this reading, fewer admitted lists means fewer groups to bring together to form a majority.

For its critics, the rule excludes votes and penalises newcomers. A bill filed in late October 2024 by PVDA-PTB members calls for article 165bis to be repealed. Its authors argue that the threshold favours the large traditional parties, and cite 380,427 votes cast in 2014 for lists that won no seat (document 56 0489/001). In 2003, the explanatory memorandum of a N-VA text noted that the party had won only one seat in the Chamber, against at least two without a threshold.

These are arguments attributed to their authors, set out here in equal measure. This site takes no side.

Sources: Chamber of Representatives, results of the federal election of 9 June 2024; Federal Public Service Home Affairs, record form A/24; Electoral Code, article 165bis; parliamentary documents 51 0251/001, 51 0584/004 and 56 0489/001; RTBF; Wikipedia, 2024 Belgian federal election. The vote bars in the table are estimates calculated from published percentages. To find the constituency where you vote, see find your constituency, and for how the site compares parties, the methodology, which recalls that the published scores describe a position on an axis and never a quality.