Are U.S. Presidents Getting Older?

Joe Biden and Donald Trump are the oldest presidents ever to be inaugurated in the United States. While Biden was 78 years old in 2021 and remains a one-term president, Trump was 70 at the time of his inauguration in 2017 and is 78 starting his second, non-consecutive term on Monday. Ronald Reagan, who was 69 years old in 1981, comes third. Like Biden, Trump's age will be 82 when finishing his term. Biden would have been 86 years old at the end of a hypothetical second term.

Taking a look at all presidents’ ages at the time of their inauguration since 1789, no clear trend is visible. Before Trump and Biden, presidents’ ages were actually well below average. Barack Obama took office at 47 years and 169 days, according to Potus.com, making him the fifth youngest president at the time of inauguration. Bill Clinton, who was 46 when he took over, was the third youngest - only John F. Kennedy (43) and Teddy Roosevelt (42) were younger.

Some of the oldest presidents hail from past centuries. William Henry Harrison was 68 at his inauguration in 1841 (he died a month later of typhoid and pneumonia), making him the fourth-oldest president ever. James Buchanan, who took office in 1857, was the fifth-oldest president at 65.