Attached below are documents summarizing voter turnout data for partisan and nonpartisan elections in Wisconsin.
The Wisconsin Elections Commission calculates voter turnout as a percentage of the voting-age population -- people age 18 and above -- as estimated by the Demographic Services Center of the Wisconsin Department of Administration. County-by-county census data and population estimates are available on their website. Wisconsin does not calculate turnout based on the number of registered voters, in part because the state has Election Day registration.
Wisconsin's 2022 Estimated Voting Age Population is 4,676,183.