How to share your personal Google calendar via an iCal link

1/ Within 'My Calendars' click the 3 dots option button next to the calendar you wish to share

2/ Click 'Settings & Sharing'

3/ Scroll down to the 'Integrate Calendar' section and copy the url in the section 

Public address in iCal Format

i.e https://calendar.google.com/calendar/ical/c_xxxxxxxxxxxpdi578%40group.calendar.google.com/public/basic.ics