How to find percentage of a database backup job done in SQL Server?

Script to find percentage of a database backup job is done

SELECT percent_complete
 ,*
FROM sys.dm_exec_requests
WHERE command IN (
  'RESTORE DATABASE'
  ,'BACKUP DATABASE'
  )

Elapsed time in Hours to complete the Job

SELECT command
 ,percent_complete
 ,'elapsed' = total_elapsed_time / 3600000.0
 ,'remaining' = estimated_completion_time / 3600000.0
FROM sys.dm_exec_requests
WHERE command LIKE 'BACKUP%'