Your formula is great and all, but it is outdated and not a complete story (for instance, like many have pointed out, the WDC gets a larger portion of the profit. Another example is the licensing of products sold in the theaters that is not factored in). Another example of how, while your formula can give a very rough idea of how profitable a movie MIGHT be, it is still outdated is how they deal with movie prescriptions. Movie prescriptions favor the studios. Most of the ticket price for a movie attended by someone with a movie prescription go to the studio while the theaters rely on concessions for their profits there.
I love the idea of what you are doing, don't get me wrong, but it really isn't accurate to say a movie isn't profitable just by putting it into that old formula. It just gives you a rough idea of what the average movie MIGHT be making for the studio.
Sorry, I wanted to keep my mouth shut, but the way you make it sound so absolute for the formula always catches me. There is way more movies that are profitable then what that formula says there is.