PowerShell gives you an interesting little number when you start it up:
Windows PowerShell
Copyright (C) 2016 Microsoft Corporation. All rights reserved.
Loading personal and system profiles took 542ms.
Windows PowerShell
Copyright (C) 2016 Microsoft Corporation. All rights reserved.
Loading personal and system profiles took 542ms.
I think it doesn't display if your profiles take less than 500ms to load.
EDIT: Just tested with a clean profile with the line "Start-Sleep -m xxxx" for various values of xxxx, and the message has shown up with times just above 500ms but not below.