How old do citizens have to be to vote for President?

In the United States, citizens must be at least 18 years old to vote for President. This age requirement is set by the 26th Amendment to the U.S. Constitution, which was ratified in 1971. Prior to the ratification of this amendment, the voting age had been 21 in most states.

The 26th Amendment was enacted in response to widespread protests and advocacy during the Vietnam War era. It aimed to address the discrepancy between the minimum age for military service, which was 18, and the voting age, which was higher. The amendment lowered the voting age to 18, granting the right to vote to millions of young Americans.

Since the ratification of the 26th Amendment, citizens who have reached the age of 18 are eligible to vote in federal elections, including presidential elections. However, it's worth noting that voter registration requirements and procedures may vary by state, and citizens must ensure they are registered to vote in accordance with their state's regulations in order to participate in elections.