Independence Avenue at peak crowd density. Composite image by Joe Ward based on video from Urdu Voice of America

The women’s march in Washington was roughly three times the size of the audience at President Trump’s inauguration, crowd counting experts said Saturday.

Marcel Altenburg and Keith Still, crowd scientists at Manchester Metropolitan University in Britain, analyzed photographs and video taken of the National Mall and vicinity and estimated that there were about 160,000 people in those areas in the hour leading up to Mr. Trump’s speech Friday.

They estimated that at least 470,000 people were at the women’s march in Washington in the areas on and near the mall at about 2 p.m. Saturday.

The two images below show the crowds when they were at their peak density at the two events.

2017 Trump inauguration 58th Presidential Inaugural Committee 2017 Women’s march ABC News Footage

The estimates are not comprehensive counts and were necessarily limited by the availability of photographs and video that covered the areas of interest. But their estimate was in line with one given by a city official who said that march participation likely surpassed half a million, according to The Associated Press.

A Metro official said that more than a million rail trips were taken Saturday, the second-highest day in its history after Barack Obama's first inauguration in 2009. More than 570,000 rail trips were taken on Friday.

The scientists had better images for the analysis of Mr. Trump’s inauguration crowd, which was concentrated on the mall. But the women’s march was more sprawling and fluid, so the actual number of people at the women’s march could be larger.

It is likely that the timing and location of the march — on a weekend, in a Democratic city in a Democratic region — helped drive the significant turnout.

In addition to wide-angle images, the scientists made use of news images that provided closer views of the crowds, which allowed them to calculate the density of specific areas more precisely.

For the women’s march, they chose a period in time when the crowd was moving the least, from 1:30 p.m. to 2:15 p.m. Using aerial footage and photographs from various angles, the analysts isolated areas with an average density of 2.5 people per square meter, the same method used at Mr. Trump’s inauguration the day before.

The maps below show the areas that they determined to be high crowd density at each event.

2009 Obama Highest density areas Capitol Washington Monument Highest density areas 2009 Obama Capitol

2017 Trump 2017 Trump

Women’s march 1/4 Mile Women’s march 1/4 Mile

But Mr. Trump was clearly upset with what he felt were undercounts of his own event the day before. In a visit to the Central Intelligence Agency on Saturday, Mr. Trump falsely accused the media of lying about the size of the crowds at his inauguration, saying that when he looked out from his podium, “it looked like a million, a million and a half people,” and that the area “all the way back to the Washington Monument was packed.”

Later in the day, Sean Spicer, the White House press secretary, claimed that Friday’s event was “the largest audience to ever witness an inauguration,” even though “no one had numbers” to confirm it because the Park Service does not issue crowd estimates.

The Park Service said in 2009 that it “firmly” believed that Mr. Obama had drawn the largest crowd ever to the National Mall. The location could have also been a contributing factor for the crowds that year; about half of Washington’s population is black, and more than 92 percent of the city voted Democratic.

Mr. Spicer said that the area between the platform where Mr. Trump was sworn in and the Washington Monument could hold 720,000 people, and claimed that “all of this space was full when the president took the oath of office.”

The images below, captured 45 minutes before the respective oaths of office, show areas that were crowded with people at Mr. Obama’s inauguration that were clearly empty during Mr. Trump’s.

2009 Obama inauguration Jewel Samad/AFP/Getty Images 2017 Trump inauguration 58th Presidential Inaugural Committee

“There is a scientific explanation why the crowd size must have appeared to Trump in 2017 similar or even larger than to Obama in 2009,” said Mr. Altenburg, one of the crowd scientists.

The scientists said Mr. Trump would only have seen the tightly packed front third of the crowd, but not the back two-thirds, from his position at the podium. To make their estimates, they monitored seven live feeds all day, including those from perspectives that someone at the podium would not have been able to perceive.