Database Shrink, Backup, then Restore
The restored database will have the same file size as it had when the backup was produced.
I sometimes call the files &quot;containers&quot;. Same number of containers, and same size. They don't have to be at the same location, though (the MOVE option of the RESTORE command).
I don't know what &quot;initial&quot; you refer to above, but whatever it is, it is probably misleading you - and it doesn't change the facts I mention above. :-)
So if you backup a database which has a 100 GB file, that file will be 100 GB when you restore form that backup. If you see something else, then you are probably in a parallel universe. ;-) OR you need to be extremely specific so we follow you to 100% of what is happening. One thing that can be useful here is RESTORE HEADERONLY and RESTORE FILELISTONLY. The later will tell you what size the files will be when you restore.