calendar.google.com

2. Click on 3 dots next to your name

3. Click "Settings and sharing"

4. Scroll down and Click "Add people and groups"

5. Type the email of person you want to share

6. Click on permissions to select the type of permission allowed. Below are the options and what they do

See only free/busy (hide details):

Check when your calendar is booked and when it has free time, but not the names or other details of your events.

Tip: Events from Gmail that have the "Only me" visibility setting aren't visible to anyone you've shared your calendar with, even people with "Make changes" access, unless you change the sharing settings for the event or the default setting for events from Gmail.

See all event details:

Find details for all events except those marked as private
Find the time zone setting for the calendar
Subscribe to email alerts when events are created, changed, cancelled, RSVPed to, or coming up

Make changes to events:

Add and edit events
Find details for all events, including private ones
Find the time zone setting for the calendar
Restore or permanently delete events from the calendar's Trash
Subscribe to email alerts when events are created, changed, cancelled, RSVPed to, or coming up

Make changes and manage sharing:

Change sharing settings
Add and edit events
Find details for all events, including private ones
Find the time zone setting for the calendar
Permanently delete the calendar
Restore or permanently delete events from the calendar's Trash
Subscribe to email alerts when events are created, changed, canceled, RSVPed to, or coming up