Square Footage for XX MW

[JAGGYProof]

Done some research but haven't found any reliable information on this topic. The main question is: Is there a good rule of thumb for how much square footage is needed for X amount of miners (or X amount of MWs)?

I know, I know...it depends on so many variables (ceiling height, dimensions of miners, orientation of miners, cooling/exhaust setup, etc.). But is there a quick, back- of-the-napkin formula that would get you decently close, even if it's a conservative calculation?

Thanks for the thought power.