It't a hard one to gauge. Marvel seems to have reached saturation at this point. They have a large body of loyal fans, but it's getting harder to get new people to see the films, because you are either into Marvel or you aren't. Films like Black Panther and Captain Marvel actually have more potential, because they have specific appeals that might bring in a new audience.

I think 200m OW and 500m total domestic is realistic. 1.5B WW.

1.6. I think the comic book films have a big audience imo. No its not a thriving genre anymore where everyone has to see it. With that being said InfinityWar will be bigger than all the others. The years of build up, the number of loved characters, the consistent + Reviews/Scores, & now your fighting the big bad of uiverse. I wont be surprised if it gets close to the 2 bil mark (Iron man, spiderman,Guardians, Cap, Hulk,Thanos etc)

Like A to Z said, $1.5 bil worldwide will be easy. This is the culmination of a lot, A LOT.

My prediction is 230M opening weekend,600M domestic and 1.6-1.7B worldwide Anything more than 1.5B means a gigantic victory for marvel and Disney. But I am doubtful since the average moviegoer has only seen 3 marvel films and doesn't know this is the combination of everything in the Mcu.Even if they do I doubt they've seen enough Marvel movies to appreciate it