Following is the data I found after running 'dbcc updateusage' on a database.

ran command 'sp_spaceused' and found the following data:

database_size: 5001.00 MB
un_allocated_space: 2606.54 MB

Reserved: 2450904 KB
Data: 2117664 KB
Index Size: 472 KB
Unused: 332768 KB

On Enterprise manager for the database properties:
Size: 5001.00 MB
Space Available: 2607.17 MB

Why the space available is not equal to the unused? Am I trying to calculate in a wrong way? How do I get the space available shown in EM
from any command like 'sp_spaceused' ?

Thanks for any help.