If you’d like to share an Outlook calendar, such as a resource calendar from Outlook on your SharePoint site, follow these steps:
Navigate to the SharePoint site of your choice and create a new SharePoint calendar list on it.
1.1 Click [Gear] → Site contents
1.2 Click [New] → App
1.3 Search for “Calendar” and click on the Calendar app
1.4 Give the list a new name and create it
Once in the calendar list, click the [Calendar] tab in the [Calendar tools]
Click the [Connect to Outlook] or [Sync to Outlook] icon.
Click [Yes] or [Allow] when prompted, to establish the connection.
Select the Outlook folder and libraries to share on SharePoint, then click [Sync Now]
Now, you’re all set and events will show up from your Outlook calendar for others to see.