Open Google Calendar on a computer
In the left panel, find My calendars
Hover over the calendar you want to share
Click the three dots next to the calendar name
Select Settings and sharing
Under Share with specific people or groups, click Add people and groups
Enter the person’s email address
Choose their permission level
Click Send
If needed, make the calendar public by enabling Make available to public in the sharing settings
On mobile, open Google Calendar and use a browser if sharing options are not available in the app