SQL Database size doesn't match with the total table sizes in the database
Depending on the RDBMS being used, it is possible that the large file size as compared to summed-up table sizes is caused by any or more than one of the following:


Last database cleanup (in terms of table deletion, record deletion, etc) did not affect any disk reclamation by the OS/RDBMS
Last database cleanup does not normally affect disk space reclamation by OS/RDBMS
Indexes/constraints are being stored in other files. You won't see these when checking just table sizes.
No shrinking has been performed, though that may also possibly end up as first and/or second in this list
A possible miscalculation of table size retrieval (I just need to add this because it happens to some) and so the numbers don't tally
And maybe a few others.. Hopefully the stackers can add


I'm not saying these are definite items that impact your situation. I just mean that these may occur, and not just in your situation..


One other thing. It can also depend on the database settings for new disk allocation sizes. Say for example one allocation for a certain DB is 1GB. Once the usage exceeds that, another 1GB is added, regardless of whether or not you consumed all of it -- at the moment more allocation is required, it gets set.