Distribution of seats in the German Bundestag’s 21st electoral term

The number of seats received by a party in the Bundestag depends on its election result. The more votes a party wins in the Bundestag election, the more seats they receive. Each voter has two votes in elections to the Bundestag: the first vote, for a constituency candidate, and the second vote, which is cast for a specific party. This second vote is decisive in the composition of the Bundestag, for which the number of Members is set at 630 seats. For example, if a party receives 20 percent of second votes nationwide, they hold 20 percent of the seats in the Bundestag. 

With their first vote, voters choose a specific constituency candidate. However, the winner of a constituency only obtains a mandate if this is supported by their party’s share of second votes in the respective federal state. In principle, only parties who receive more than five percent of second votes nationwide enter into the Bundestag. Exceptions to this are the parties representing national minorities, along with those parties who win at least three direct constituency mandates.