List of presidents of the United States by age
The median age upon accession to the presidency is 55 years and 3 months. This is how old Lyndon B. Johnson was at the time of his inauguration. The youngest person to assume the office was Theodore Roosevelt, who became president at the age of , following William McKinley's assassination; the oldest was Donald Trump, who was old at his inauguration. The youngest person to be elected president was John F. Kennedy, at of age on election day; the oldest was Ronald Reagan, who was old at the time of his election to a second term.
Electoral history of Ronald Reagan
In addition to this, Reagan was the oldest person ever elected to the presidency, at the age of 69 on the date of his first presidential election victory in 1980. He was surpassed in 2016 by Donald Trump as the oldest person first elected to the presidency, but Reagan currently remains the oldest person ever elected president, in 1984 at 73.