opkomstpercentage

Opkomstpercentage is the turnout percentage in an election, referring to the share of eligible voters who cast a ballot. It is most commonly calculated as the number of ballots cast divided by the number of eligible voters, multiplied by 100. In some contexts, the denominator is the number of eligible voters (kiesgerechtigde) and the numerator includes all ballots cast, including blanks and spoiled ballots; in others, only valid votes are counted. This distinction can affect the reported rate and comparisons across elections or jurisdictions.

The term is widely used in national, regional, and local elections to gauge citizen participation and the perceived legitimacy of the mandate that results from the vote. Turnout is influenced by multiple factors, including the ease of voting (registration requirements, access to polling stations, vote-by-mail options), the presence of multiple elections on the same day, weather, political mobilization, and the perceived competitiveness or importance of the election. Societal and institutional factors, such as compulsory voting in some countries, also play a significant role.

Interpreting opkomstpercentage requires attention to methodological differences: variations in who is counted as eligible, whether overseas or non-resident voters are included, and whether early or postal ballots are captured in the tally. Data are typically reported by official election authorities or national statistics offices, and are also compiled by international organizations for comparative analysis. The indicator serves as a proxy for civic engagement and political legitimacy, but must be compared with caution due to definitional and procedural differences.