These instructions apply to accessing your Outlook calendar on the web;
" Get a link
You can give anyone a link that will give them view-only access to your calendar?and they can pass it on to others. People you give a link to can access your calendar via other calendar apps, like Microsoft Outlook, Google Calendar, Mozilla Lightning, or iCal.
You can choose from two access levels: Show event details, and Show free/busy time. You can have one set of links for each access level.
Here?s how to get a link:
In Calendar, click Share, and then click the name of the calendar you want to share.
Click Get a link.
Choose Show event details or Show free/busy time. Click Create under the type you want.
Each set of links allows people to access your calendar three different ways:
View in a web browser (HTML)
Import into other calendar apps (ICS)
View in a feed reader (XML)
No matter which link in the set they use, the permissions are the same."
Once they have your link, they can import that calendar into their Google calendar,