I don't know.
At first I didn't think the mainstream was in tune with this movie, but I've heard quite a few people talk about it, lately, that aren't normally aware of anything. Black Panther didn't manage to break that magical raw $700m barrier, but at $682m it has come as close as any film ever has without being one of the two that did it (Star Wars: The Force Awakens and Avatar), and it's also the #32 domestic movie of all time adjusted for inflation, now.
You're not going to bring the Wonder Woman crowd under this big tent, but between all the new Black Panther recruits, the Guardian of the Galaxy crowd, the mainline Avengers/Captain America/Iron Man crowds, I've come to believe that Infinity War probably won't have much difficulty in eclipsing the $700m mark, and could definitely challenge those two movies above the waterline for absolute domestic supremacy. While I think its audience to be almost wholly subsumed in these other audiences, I think there's even a tiny subset of Thor fans out there who love that franchise's campiness while not caring as much about the more serious and dramatic stuff.
The international market doesn't care as much about the sub-franchises. They're all about The Avengers. They've never added $900m to any Marvel total.
So I think it comes up just short of $2bn, raw, and finishes at #4 all-time ahead of Jurassic World. I had real trouble picking between the $1.8bn-$1.9bn and $1.9bn-$2.0bn brackets.