The Women's March on Washington and its sister protests dominated the streets and the news this weekend as creative-sign-carrying, pink-hat-wearing masses came out to advocate for women's rights under new U.S. President Donald Trump. As Trump and his administration debated the size of the crowd that attended his inauguration, photos of the Saturday demonstration in the capital showed the National Mall blanketed with activists. Some data experts even declared the nationwide march the largest protest in American history.

Whether you participated or watched from afar, you may be wondering just how many people went to the march. Here's what to know for your Monday watercooler discussion:

Organizers initially predicted about 250,000 people would attend the Women's March on Washington, according to the Washington Post. Turnout far exceeded that.

The Washington Metropolitan Area Transit Authority, which runs the trains in the capital, announced on Twitter that it saw 1,001,616 riders Saturday. That means Saturday was the subway system's second busiest day ever, second only to former President Barack Obama's 2009 inauguration, according to the Huffington Post.

Crowd scientists Marcel Altenburg and Keith Still told the New York Times that, as of 2 p.m. EST on Saturday, there were a minimum of 470,000 people near the National Mall.

Christopher Geldart, the director of the District of Columbia's homeland security and emergency management agency, told the Associated Press there were more than 500,000 protesters in total.

Jeremy Pressman, of the University of Connecticut, and Erica Chenoweth, of the University of Denver, were maintaining a spreadsheet Monday where they compiled updated crowd estimates. Pressman and Chenoweth found that, in addition to the New York Times' estimate, a Facebook source said 680,000 people had attended. But they noted the Guardian reported "1 million people marched in the historic Women’s March on Washington on Saturday, according to initial estimates."