Donald Trump was born on 14 June, 1946, which makes him 70 years old at the time of his inauguration. He will be the 45th US president — and the oldest to have ever taken office at his start date in American history.

Ronald Reagan was 69 when he became US president in 1981. Reagan was a two-termer, and he was 77 by the time he left office in 1989. If Trump also becomes a two-termer, he would be 78 when he left office in 2025, setting a new record.

The youngest US president was Theodore "Teddy" Roosevelt, who was just 42 when he entered the White House in 1901. And the youngest US president at the time they left office was John F. Kennedy, assassinated in 1963 aged 46.

Trump's inauguration on 20 January, 2017, will begin at midday in Washington, DC (which is 5pm GMT). Trump will be sworn-in by the Chief Justice of the United States. Trump will take the following Oath of Affirmation: "I do solemnly swear (or affirm) that I will faithfully execute the office of president of the United States, and will to the best of my ability, preserve, protect and defend the constitution of the United States."

He'll then deliver his inaugural address to the thousands expected to gather in front of the Lincoln Memorial. Although 250,000 tickets were available, the Joint Congressional Committee on Inaugural Ceremonies says it expects a total crowd of three times that size to join the parade, including protesters.

Only certain areas of the parade route, which takes place on Pennsylvania Avenue – the street connecting the White House and the Capitol building – are ticketed. In the past, the parade has begun at around 2.30pm local time and lasts for around two hours.

But just as Trump demanded to see his predecessor Barack Obama's birth certificate, perhaps we should demand to see his — seems to think he's really 85.

Donald Trump
Donald Trump says he is 70, but this analysis of his photo thinks he is 85