What would you consider something like $35m/$305m?

Disappointment: $39m or lower opening / $119m or lower total
Breakout: $81m or higher opening / $251m or higher total

This movie is made for disappointment. Basically, many are saying if it doesn't out-open Last Stands nearly 123M Memorial Day weekend, it's a disappointment. That was the peak of the franchise coming off the most well-liked movie. While it had a fair amount of competition, it had less direct competition than DoFP does. The last two movies in the franchise had 3 day OW of about 55 and 53M. You have to give some credit for the goodwill from Frist Class, the time travel-mix-up-the-cast premise, inflation, and 3D. But even so, I wouldn't be disappointed unless it failed to hit 90M for the 4-day weekend, or 200M total.

I think it's a breakout if it does Last Stand #'s OW, and/or beats 250M total.

The following analysis from back in January had predicted Godzilla would flop, partially based on weak marketing...

Is 'Godzilla' The 'John Carter' Of 2014?

Clearly, the producers took heed of these warnings and poured the bank into marketing the hell out of this - - with special attention on misdirecting potential ticket buyers from finding out just how lame the actual story is.

Is there any word on what the marketing budget was?

“Godzilla” arrives with a $160 million production budget and when marketing and other costs are taken into account, Legendary Pictures says that it will need to make $380 million globally in order to break even....

CLARIFICATION: In an earlier version, the amount needed for “Godzilla” to break even was given as $450 million by a source close to the company. Legendary says that figure is incorrect.