A voting age is a minimum age established by law that a person must attain before they become eligible to vote in a public election. As of the present day, the most common voting age is 18 years; however, voting ages as low as 16 and as high as 25 currently exist (see list below). Most countries have set a minimum voting age, often set in their constitution. In a number of countries voting is compulsory for those eligible to vote, while in most it is optional.
When the right to vote was being established in democracies, the voting age was generally set at 21 or higher. In the 1970s many countries reduced the voting age to 18. The debate is ongoing in a number of countries on proposals to reduce the voting age to or below 18. In Brazil, for example, the minimum age lowered from 18 to 16 years old in the 1988 constitution.