Voter Turnout Rate Calculator: Votes Cast as a Share of Eligible Voters
Work out a voter turnout rate from votes cast and the voter base — the standard measure of electoral participation — with the non-voting share shown alongside.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Turnout rate | Did not vote |
|---|---|---|
| 13,800 of 20,000 (69%) | 69.00% | 31.00% |
| 5,500 of 10,000 (55%, midterm) | 55.00% | 45.00% |
| 1,500 of 10,000 (15%, local election) | 15.00% | 85.00% |
| 8,000 of 10,000 (80%, high turnout) | 80.00% | 20.00% |
How This Calculator Works
Enter the number of votes cast and the size of the voter base (registered voters, eligible population, etc.). The calculator divides one by the other and multiplies by 100 to give the turnout rate, with the non-voting share alongside. Be consistent about which base you use, since it changes the figure.
The Formula
Part as a Percentage of a Whole
Part is the portion, Whole is the total it belongs to
Worked Example
13,800 votes cast out of 20,000 eligible voters is a 69% turnout rate, with 31% not voting. Turnout is a core measure of democratic participation, but the headline number depends heavily on the denominator: turnout as a share of registered voters is usually higher than turnout as a share of the voting-eligible population (which includes eligible people who never registered), and both differ from the voting-age population (which may include non-citizens or others ineligible). Comparisons are only meaningful when the same base is used.
Key Insight
Voter turnout is a simple ratio whose interpretation hinges entirely on the denominator — a point that causes frequent confusion in reporting and comparisons. Three common bases give different rates from the same votes: registered voters (the narrowest, yielding the highest turnout, since you've excluded the unregistered), the voting-eligible population or VEP (all eligible citizens whether or not registered, the base many political scientists prefer for cross-election comparison), and the voting-age population or VAP (everyone of voting age, which can include non-citizens and ineligible felons, giving the lowest rate). So a '69% turnout' means very different things depending on the base — always note which one. Turnout also varies systematically: presidential/general elections draw far higher turnout than midterms, primaries, or local elections; it differs by demographic, region, and the ease of voting (registration rules, mail/early voting, holiday status); and it's a closely watched indicator of civic engagement and election legitimacy. For valid comparisons across places or years, hold the base constant and compare like elections (general to general, not general to primary). This calculator gives the clean rate and the non-voting complement; the analytical work is choosing and labeling the denominator and comparing comparable elections.
Frequently Asked Questions
How is voter turnout rate calculated?
Divide votes cast by the voter base, then multiply by 100. 13,800 votes out of 20,000 eligible voters is a 69% turnout rate, with 31% not voting.
Which denominator should I use — registered or eligible voters?
It depends on the question, but be consistent. Turnout as a share of registered voters is highest (the unregistered are excluded); as a share of the voting-eligible population (VEP) it's lower but better for comparing elections; as a share of voting-age population (VAP) it's lowest. Always label which base you used.
Why do reported turnout figures differ?
Mainly because of the denominator. The same votes produce different turnout rates depending on whether you divide by registered voters, eligible voters, or voting-age population. Different sources use different bases, so figures that seem to disagree often just use different denominators — check the base before comparing.
Why does turnout vary so much between elections?
Election type matters most: presidential/general elections draw far higher turnout than midterms, primaries, or local races. Turnout also varies by demographics, region, and how easy voting is (registration rules, mail/early voting). For fair comparison, compare like elections — general to general, not general to primary.
What does the non-voting share tell me?
It's 100 minus the turnout rate — the share of the voter base that didn't cast a ballot. It's a measure of potential participation not realized, and a focus for get-out-the-vote efforts. As with turnout, it depends on the denominator, so interpret it against the same base.
Related Calculators
Methodology & Review
The turnout rate is votes cast divided by the voter base, multiplied by 100. The complement is the non-voting share. The rate depends on the base used — registered voters, the voting-eligible population, or the voting-age population — which can produce notably different figures.
Written by Ugo Candido · Last updated May 22, 2026.