In Bundestag elections, the allocation of seats is based on proportional representation and a candidate-centred election. The system combines two elements: the first vote elects a constituency candidate. The candidate who obtains most votes wins (majority voting). The second vote goes to the Land list of a party. The number of second votes determines the number of Bundestag seats a party receives (proportional representation) and therefore is decisive.
The procedure for calculating the distribution of seats was last modified by the 22nd Ordinance amending the Federal Elections Act of 3 May 2013 (Federal Law Gazette I p. 1082). It uses the Sainte-Laguë/Schepers procedure in a two-stage calculation process, with two steps per stage.
The final distribution of seats is not yet calculated at this stage but the minimum number of seats each party is entitled to (seat contingent).
First the 598 Bundestag seats initially available are distributed among the individual Länder on the basis of the share of the German population living there.
Second, the seats going to each Land are distributed among the parties in accordance with the second votes they have won in the respective Land. Parties which have obtained less than 5 % of the second votes cast (restrictive clause) and have not won at least three constituency seats (clause on the minimum number of constituency seats required for party representation in Parliament) are not considered in the distribution of seats. Therefore, votes cast for parties which do not overcome the 5 per cent threshold do not have an impact on the distribution of seats in the Bundestag.
In the exceptional case that a party wins more constituency seats in a Land than it is entitled to by the second votes it has won (overhang mandates), it will receive these seats anyway.
The final distribution of seats is calculated in stage 2. The main objective is allocating to each party a number of seats which exactly corresponds to the second votes it has won.
To this end, the number of seats a party is entitled to in all of Germany is determined on the basis of the second votes it has obtained. However, this result may be modified by the minimum number of seats determined in stage 1 and the overhang mandates calculated. To guarantee proportional representation based on second votes, the Bundestag is enlarged by additional mandates in such cases. The total number of Bundestag seats to be distributed is increased by additional balance seats until every party has received just as many seats as it is entitled to by the second votes it has won, including the minimum number of seats and the overhang mandates calculated. When there are no modifications, however, the size of the Bundestag remains unchanged at 598 seats.
The second step determines how many of a party’s seats, as calculated before, go to each of its Land lists. This depends on the number of second votes the party has obtained in each Land. In any case it will receive the constituency seats it has won in the Land.
The result is a parliament (Bundestag) where the seats are distributed in accordance with the number of second votes cast.
In European elections the 96 seats of the German deputies are assigned in line with proportional representation only. Every person entitled to vote has only one vote to be cast for a list. Every party or political association of voters may draw up a list for all Länder or lists for individual Länder, the latter are usually regarded as one nomination.
Since the 2009 European Election the seats have been distributed in accordance with the Sainte-Laguë/Schepers calculation method. All votes cast for the same nomination are added up.
In European elections there is no such restrictive clause as the 5 per cent threshold of Bundestag elections. The Federal Constitutional Court declared unconstitutional both the former 5 % restrictive clause and the 3 % restrictive clause introduced as its substitute. This means that all political parties are considered when the seats are distributed.