Note: If you've received an email invitation to a calendar, you can select the link in the email invitation to add the calendar to your calendar view. Otherwise you can follow steps outlined below to add the calendar manually:

1. Log into Outlook on the web.
2. Go to your Calendar view.
3. Click Add calendar on the left hand side.
4. Select Subscribe from web on the left hand side of the pop-up. Note: To add another Office 365 calendar (user or resource), select Add from directory.
5. After you've entered the desired calendar or URL, select Import to add the calendar.
6. The calendar will be added to your list of calendars.

For instructions on how to obtain the calendar URL for your Google Calendar, please see the "Get your calendar (view only)" section of this Google Support document.