Determining ms sql db size

Hello, this morning i needed a task to be accomplished: understand what is the dimension of a couple of databases standing on a windows server 2003 with sql server 2005.
Here it is the walkthrough:
- start-> run -> cmd
- sqlcmd
- USE master;
- EXEC sp_spaceused;
- go
and that’s all.
References: http://msdn.microsoft.com/en-us/library/ms188776.aspx