Space Used by Database Files
Retrieve data about size and space used for all the files in the current database with this script. Some tips on database file size management:
Make sure there is enough unallocated space for future growth.
If the value of “UnallocatedSpace_Percent” is low, consider allocating more space in the next maintenance window.
Auto-growth should be enabled as a safety measure.
Do not attempt to shrink files, unless you really have to. See this post on When and How to Shrink Your Database for more information.