For your dev, test and production environments, what is the size ratio between environments?

This is partially documented here but as has already been said, depends on the size of your user base amongst other things. Linked from that document page is the documentation for the sizing script, which may also help.

This is partially documented here but as has already been said, depends on the size of your user base amongst other things. Linked from that document page is the documentation for the sizing script, which may also help.