Through below Script we are able to find out the User database Size in SQL Server.
Check User database size in SQL Server :-
SELECT DB_NAME(database_id) AS Database_Name, SUM((size*8)/1024.0/1024.0) Size_In_GB FROM sys.master_files WHERE DB_NAME(database_id) in (select name from sys.databases where name not in ('tempdb','master','msdb','model')) group by DB_NAME(database_id)
Output:-