To get recent size of all databases on an instance, I have found following simple query very useful.
ROUND(SUM(mf.size) * 8 / 1024, 0) Size_MBs
FROM sys.master_files mf
INNER JOIN sys.databases d ON d.database_id = mf.database_id
WHERE d.database_id > 4 GROUP BY d.name
ORDER BY d.name
Aasim Abdullah is working as SQL Server DBA with CureMD (www.curemd.com) based in NY, USA. He has been working with SQL Server since 2007 (Version 2005) and has used it in many projects as a developer, administrator, database designer. Aasim's primary interest is SQL Server performance tuning. If he finds the time, he like to sketch faces with graphite pencils.