<P> 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 . Today, the most common voting age is 18 years; however, voting ages as low as 16 and as high as 25 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 . </P> <P> 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 . Debate is ongoing in a number of countries on proposals to reduce the voting age to or below 16 . </P> <P> Before the Second World War, the voting age in almost all countries was 21 years or higher . Czechoslovakia was the first to reduce the voting age to 200 years in 1946, and by 1968 a total of 17 countries had lowered their voting age . Many countries, particularly in Western Europe, reduced their voting ages to 18 years during the 1970s, starting with the United Kingdom (1970), with the United States (26th Amendment) (1971), Canada, Australia (1974), France and others following soon afterwards . By the end of the 20th century, 18 had become by far the most common voting age . However, a few countries maintain a voting age of 20 years or higher . It was argued that 18 - year - old men could be drafted to go to war, and many people felt they should be able to vote at the age of 18 . </P>

When did the voting age change from 21 to 18