What would a breakdown look like for that? Is it split into marketing & production cost?
We know that the budget of the film doesn't include marketing and certain administrative costs. But marketing costs vary from film to film and the studios almost never reveal that amount. So, as a rule of thumb, the trade magazines use 50% of the budget for those extra costs.
We know that in the U.S. a major film's split between studio/theater can be anywhere from 55/45 to 65/35, but only at first. The longer the film remains in the theaters, the larger the theater's split until the studio is getting less than 50%. Also, overseas, the studio's split starts at *less* than 50%. So, the rule of thumb is to just average it out to 50/50.
So, you take the film's budget and add 50%. Then you take the BO receipts and split them in half. Then you note the difference.
In the end, to 'break even,' a film's BO needs to be three times the budget for the studio to break even.
An example (in millions):
Budget: $200
Budget + Marketing: $300.
BO: $800.
Studio's take of BO: $400.
Studio's profit: $100
Because we don't have exact numbers, if a film's profit/loss is within +/-$10M, that should pretty much be taken as 'break even.'