Check the Progress of Shrink Database

You can use SSMS GUI or DBCC SHRINK command to shrink the size of the data and log files in a specified database. By the way, both the SSMS GUI and DBCC command do NOT tell you the progress of it. You can consult the sys.dm_exec_requests DMV's percent_complete column to check the progress as demonstrated below:

SELECT percent_complete, start_time, [status], command, estimated_completion_time, cpu_time, total_elapsed_time FROM sys.dm_exec_requests WHERE percent_complete > 0
 
You should look for DbccFilesCompact in the command column.