I think that script have a little mistake. Field size in table sys.master_files contains current filesize in 8-KB pages. So, this part of script is not right:Sum(Convert(decimal(10,2),tds.Size)) * 8000)/1024)/1024. Author wants to get file size in MB, but it must be like this: Sum(Convert(decimal(10,2),tds.Size)) * 8192)/1024)/1024. But the easiest way to get file size in MB is to write this: Sum(Convert(decimal(10,2),tds.Size)) * 8/1024