Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
If you are using the desktop Office applications for Windows, they will follow the system settings by default. You can specify metric vs US (imperial) independently of your region:
But you can also specify the units in some of the Office applications:
Word: File > Options > Advanced, section Display: 'Show measurements in units of' drop-down.
Excel: File > Options > Advanced, section Display: 'Ruler units' drop-down.