“Turnout” refers to the extent of popular participation in elections. Turnout is usually measured as a ratio. The numerator of the ratio is the number of votes cast. Various measures may be used as the denominator: (1) The Voting Age Population—broadly speaking it is the population above the legal voting age; (2) Voting Eligible Population—all citizens who are not excluded from voting because of some legal impediment; (3) Registered voters.
Reported measures of each of these has varied somewhat over time as estimates have been revised and refined. With the exception of total votes cast, these numbers are estimates from census data or census surveys between the decennial census.
Three propositions underlie most research on turnout.
- First: turnout may reflect the health of popular democracy. Well-functioning democracies are more inclusive and will have higher turnout.
- Second: Ease of registration affects turnout. In comparing two jurisdictions over time with comparable demographic characteristics (education, age, income, etc.), turnout should be higher in the one with less restrictive registration requirements.
- Third: Electoral competition should drive up turnout. Other things equal, when the stakes in the election seem greater, turnout should increase.
Voting Age Population (VAP) is typically calculated based on census data (“resident population [21 or 18] years and older”). Before 1920 the numbers used are always adjusted for the shifting definition of citizens with voting rights. So women are excluded before 1920. The classic attempt to define the voting age population for the 19th century is by Walter Dean Burnham, “The Turnout Problem” in Elections American Style ed., Reichley (Brookings: Washington D.C., 1987) Burnham published only the turnout ratio, not his actual estimate of the voting age population! Our data on Voting Age Population are drawn from Census publications. There does not seem to be a single source that can serve as a data source for all observations back to 1932. The data for 2020 are found at this link. Some historical data back to 1964 are found at this page. Searching at the Census website on "Voting and Registration" is usually successful. Some data have been published in a Press Release or Report P20.
Voting Eligible Population (VEP) is an attempt to make an even more precise definition of the population of people who have a legal right to vote—potential voters. Making the estimates of noncitizens and disfranchised felons has been carried out mostly by Professor Michael McDonald and data are published in the U.S. Elections Project website. In many instances, the Census reports identify the number of non-citizens included in the VAP. By our calculation, subtracting that report of the number of non-citizens from the reported VAP yields a smaller VEP than reported at the US Elections Project. The US Elections Project data are also based on census and survey reports.
Registered voters counts the total number of eligible people who have taken the additional step of actually registering to vote. We report here the estimates produced by the Census Bureau’s Current Population Survey. This revised table no longer reports registration totals before 1968, consistent with recent CPS publications. Registration was not a universal requirement until “well into the twentieth century” (Ansolabhere and Konisky) and some states did not impose uniform registration requirements until the 1970s. As of 2016, North Dakota had no registration requirement. So it is possible for the number of votes to exceed the number of registered voters. That is the case with the numbers reported above for 1960.
Scholars point out that census data may not be entirely accurate with respect to registration (see Bennett 1990). A data source that may be of interest to many is the U.S. Election Assistance Commission which surveys county-level officials about voting and elections. Among their data is a series reporting the total number of persons "registered and eligible to vote." For 2016, the sum of the individual county numbers, for counties with data in the US is 185,714,229--a number 15% greater than the CPS estimate for the same year and election.
| Year | Turnout | Voting Age Population (VAP) |
Voting Eligible Population (VEP) |
Registered Voters |
Turnout as % VAP |
Turnout as % VEP |
| 1828 | 57.6% | |||||
| 1832 | 55.4% | |||||
| 1836 | 57.8% | |||||
| 1840 | 80.2% | |||||
| 1844 | 78.9% | |||||
| 1848 | 72.7% | |||||
| 1852 | 69.6% | |||||
| 1856 | 78.9% | |||||
| 1860 | 81.2% | |||||
| 1864 | 73.8% | |||||
| 1868 | 78.1% | |||||
| 1872 | 71.3% | |||||
| 1876 | 81.8% | |||||
| 1880 | 79.4% | |||||
| 1884 | 77.5% | |||||
| 1888 | 79.3% | |||||
| 1892 | 74.7% | |||||
| 1896 | 79.3% | |||||
| 1900 | 73.2% | |||||
| 1904 | 65.2% | |||||
| 1908 | 65.4% | |||||
| 1912 | 58.8% | |||||
| 1916 | 61.6% | |||||
| 1920 | 49.2% | |||||
| 1924 | 48.9% | |||||
| 1928 | 56.9% | |||||
| 1932 | 39,816,522 | 75,768,000 | 52.6% | |||
| 1936 | 45,646,817 | 80,055,000 | 57.0% | |||
| 1940 | 49,815,312 | 84,319,000 | 59.1% | |||
| 1944 | 48,025,684 | 90,599,000 | 53.0% | |||
| 1948 | 48,833,680 | 94,877,000 | 51.5% | |||
| 1952 | 61,551,919 | 98,113,000 | 62.7% | |||
| 1956 | 62,027,040 | 102,743,000 | 60.4% | |||
| 1960 | 68,836,385 | 108,458,000 | 63,854,789 | 63.5% | ||
| 1964 | 70,097,935 | 110,604,000 | 73,715,818 | 63.4% | ||
| 1968 | 73,026,831 | 116,353,000 | 81,658,180 | 62.8% | ||
| 1972 | 77,625,152 | 136,203,000 | 98,480,000 | 57.0% | ||
| 1976 | 81,603,346 | 146,548,000 | 97,761,000 | 55.7% | ||
| 1980 | 86,496,851 | 157,085,000 | 147,870,815* | 105,035,000 | 55.1% | 58.4% |
| 1984 | 92,654,861 | 169,963,000 | 167,701,904 | 116,106,000 | 54.5% | 55.2% |
| 1988 | 91,586,725 | 178,098,000 | 173,579,281 | 118,589,000 | 51.4% | 52.8% |
| 1992 | 104,600,366 | 185,684,000 | 179,655,523 | 126,578,000 | 56.3% | 58.2% |
| 1996 | 96,389,818 | 193,652,000 | 186,347,044 | 127,661,000 | 49.8% | 51.7% |
| 2000 | 105,594,024 | 202,609,000 | 194,331,436 | 129,549,000 | 52.1% | 54.3% |
| 2004 | 122,349,480 | 215,694,000 | 203,483,455 | 142,070,000 | 56.7% | 60.1% |
| 2008 | 131,406,895 | 225,499,000 | 213,313,508 | 146,310,000 | 58.3% | 61.6% |
| 2012 | 129,139,997 | 235,248,000 | 222,474,111 | 153,160,000 | 54.9% | 58.0% |
| 2016 | 136,787,187 | 245,502,000 | 230,931,921 | 157,596,000 | 55.7% | 59.2% |
| 2020 | 158,481,688 | 252,274,000 | 242,690,810 | 168,308,000 | 62.8% | 65.3% |