DBCC CHECKDB is failing on a particular database because of
Could not allocate space for object 'dbo.SORT temporary run storage: 143479689576448' in database 'tempdb' because the 'PRIMARY' filegroup is full. Create disk space by deleting unneeded files, dropping objects in the filegroup, adding additional files to the filegroup, or setting autogrowth on for existing files in the filegroup.
Tempdb is currently 5GB. The database in question is 56GB. The biggest table in that db is 15GB.
How big shall I make tempdb?