[RightField]

The National Park Service used 1 person per 2.5 square feet when estimating the crowd at 0's inauguration. (Scroll down to the bottom of the article.) Imagine using that number for THIS rally.

[RightField]

Another oops from RightField:

The article says average density is 1 person per 5 sq ft.
Tightly packed crowds are 1 person per 2.5 sq ft.

[muawiyah]

It is always cold for inaugurations and the crowds pack in closer ~ if only to block the wind.

[airedale]

That would put it at well over 600k. But 2.5 per person seems like a lot. Some areas in the photos closer to the Washington Monument they are pretty spread out. Also a good part of the area is covered by large trees. The trunks eat space.. If you use 2x3 per person or 6 sq ft it’s over 250k probably closer to 300k because of the side with the lake I didn’t calculate