List of presidents of the United States by age

Article Two of the United States Constitution provides that U.S. presidents must be at least 35 years old at the time they take office.

[1][2] The youngest person to become U.S. president was Theodore Roosevelt at age 42, who succeeded to the office after the assassination of William McKinley.

[1] The oldest person inaugurated president is Donald Trump, at age 78 years, 7 months, for his second term.

[4] The oldest president at the end of his tenure is Joe Biden at age 82 years, 2 months.

[6] Carter's retirement at 43 years, 344 days, is the longest in American presidential history.