Checking database file free space

 select
       name
     , filename
     , convert(decimal(12,2),round(a.size/128.000,2)) as FileSizeMB
     , convert(decimal(12,2),round(fileproperty(a.name,'SpaceUsed')/128.000,2)) as SpaceUsedMB
     , convert(decimal(12,2),round((a.size-fileproperty(a.name,'SpaceUsed'))/128.000,2)) as FreeSpaceMB
     from dbo.sysfiles a