The day after his inauguration, President Donald Trump gave a speech at the CIA headquarters in which he accused the media of lying about the size of the crowds which saw his swearing-in at the Capitol.

"I get up this morning, I turn on one of the networks, and they show an empty field," he said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 36 seconds 36 s Press secretary critical of Trump's inauguration coverage

But he said while the network put the crowd at 250,000, that is not what he could see as he gave his inaugural speech.

"It looked like a million-and-a-half people ... it went all the way back to the Washington Monument," Mr Trump said, adding that the media had been caught out and would "pay a big price".

Later, his press secretary Sean Spicer went even further, saying it was "the largest audience to ever witness an inauguration, period, both in person and around the globe".

So how many people were actually there?

There are no official estimates any more (the National Park Service stopped providing them in the 90s) but it is nevertheless clear that the crowds were not as big as Team Trump says.

This is the crowd that Mr Trump could see as he delivered his speech:

What President Donald Trump could see during his inaugural address. ( Reuters: Ricky Carioti )

But while it may have looked like the crowd extended to the Washington Monument, here is a better perspective (along with a photo taken around the same time back in 2009 at Barack Obama's first inauguration):

Photos taken around the same time of day show what the first inaugurations of Donald Trump (left) and Barack Obama looked like from above. ( Reuters: Lucas Jackson, Stelios Varias )

Thin crowds and partially empty stands also dotted Mr Trump's inaugural parade route:

US President Donald Trump gives a thumbs up during his inaugural parade. ( Reuters: Carlos Barria )

Hotels across the District of Columbia reported vacancies, a rarity for an inauguration.

Another good way of measuring attendance is looking at how many people used Washington's rail system during the inauguration.

As of 11am on Friday, 193,000 trips had been taken via the Washington Metro system. At the same hour eight years ago, at Mr Obama's first inauguration, there had been 513,000 trips. Four years later, there were 317,000.

In total, the Washington Metro told the Washington Post that 570,557 people took trips on Friday between 4am and midnight. By comparison, the totals for Mr Obama's inaugurations in 2009 and 2013 were 1.1 million and 782,000 respectively.

What about TV viewership?

Nielsen estimates 31 million people in America watched TV coverage of the inauguration.

That audience total, measuring continuous coverage by 12 broadcast and cable networks, did beat the 20.6 million who viewed Mr Obama's second inauguration in 2013.

But a president's second swearing-in typically sees a drop-off in viewership. Mr Obama's first inauguration in 2009 was seen by 37.8 million people.

The most-watched inauguration since 1969 was President Ronald Reagan's first oath-taking in 1981, which was seen by 41.8 million people.

ABC/wires