But how can you know how many floors they have? And where are you getting the list of buildings from? And what makes you think your list is complete?

Also how do you know their efficiency? Google might have less space but also a way to pack twice as much compute in the same place.

Like I said, this is impossible to know without a lot of insider information from a lot of companies.

Well, they tell you for one: https://datacenterpost.com/scaling-up-google-building-four-s... We also have Google Street view, etc.

Of course, it's all estimates. You can get fancier and count generators and transformers and stuff too.