SOLVED Space occupied by Snapshoot.

[DarkCorner]

Mine will surely be a trivial question, but searching online I couldn't find an answer.
I would like clarification on how snapshoots take up disk space.
Example: 10GB disk busy.
With a first snapshot the space occupied should have remained the same.
I add new files for 1GB, now the disk space is 11GB.
Taking a snapshot now, how much disk space is there?
Is it still 11GB or is it 11GB, plus 1GB of snapshots?

Instead, if I now modify 1GB of files, the disk space remains 11GB, but after a further snapshoot, how much space is occupied?

I'm scheduling hourly snapshots with one day retention and one snapshot per day with one week retention.
I'm doing some calculations to avoid filling the disk only with snapshots.

 

[NugentS]

A snapshot adds no disk space useage. Anything you add afterwards increases space. Even replacing a file increases space. Deleting a file that has been snapshotted does not reduce space used as the file is still in the snapshots