I have an application on SQL Server. A file has grown to say 18 gig and the reserved space for this is 18.1. We have 22.6 unused space. At what point does the file know to grow into the unused space... and is there a way to determine how much of the unused space the file will takeover.

My appologies if this is the incorrect area to post this... i will do better next time...

Thanks in advance for any information