@ehBeth,
Every U.S. President
age at time of inauguration.
Average median age of U.S. president at inauguration is
55.
Theodore Roosevelt was youngest at inauguration at age
42.
Ronald Reagan was the oldest at second term inauguration at age
73.
1. George Washington 57 and 61
2 John Adams 61
3 Thomas Jefferson 57 and 61
4 James Madison 57 and 61
5 James Monroe 58 and 62
6 John Q. Adams 57
7 Andrew Jackson 61 and 65
8 Martin Van Buren 54
9 William H. Harrison 68
10 John Tyler 51
11 James K. Polk 49
12 Zachary Taylor 64
13 Millard Fillmore 50
14 Franklin Pierce 48
15 James Buchanan 65
16 Abraham Lincoln 52
17 Andrew Johnson 56
18 Ulysses S. Grant 46 and 50
19 Rutherford B. Hayes 54
20 James A. Garfield 49
21 Chester A. Arthur 51
22 Grover Cleveland 47
23 Benjamin Harrison 55
24 Grover Cleveland 55
25 William McKinley 54
26 Theodore Roosevelt 42 and 46
27 William H. Taft Sep 51
28 Woodrow Wilson 56 and 60
29 Warren G. Harding 55
30 Calvin Coolidge 51 and 56
31 Herbert Hoover 54
32 Franklin D. Roosevelt 51, 55, and 59
33 Harry S. Truman 60 and 64
34 Dwight D. Eisenhower 62 and 66
35 John F. Kennedy 43
36 Lyndon B. Johnson 55
37 Richard Nixon 56
38 Gerald Ford 61
39 Jimmy Carter 52
40 Ronald Reagan 69 and 73
41 George H. W. Bush 64
42 Bill Clinton 46 and 50
43 George W. Bush 54 and 58
44 Barack Obama 47 and 51
45 Donald Trump 70
https://en.m.wikipedia.org/wiki/List_of_presidents_of_the_United_States_by_age