Jessie, I did some searching and found that you should add a param to the sp_spaceUsed proc. This will give you a more accurate value.

EXEC sp_spaceused @User_Table_Name,'true'

I also used this to get the unused KB's for each table

Unused_KB = CONVERT(int, LEFT([unused], PATINDEX('% KB', [unused]) - 1))

Thanks again.