Instructions apply to Google Calendar on the web.
it’s possible for you to’t export events from the Google Calendar app.
Open Google Calendar on your machine.

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On the top right, selectSettings(gearicon) and then selectSettingsfrom the drop-down list.
SelectImport & exportto download your events.
Under Export, selectExport.
A ZIP file will download to your machine.
If you kick off the ZIP file, you’ll find individual ICS files for each of your calendars.
Export Events From a Single Calendar
On the left side of the page, find theMy calendarssection.
(You may need to select it to expand it.)
Point to the calendar you want to export.
Select theMore icon(three dots) followed bySettings and sharing.
UnderCalendar controls, selectExport calendar.
An ICS file of your events will start to download.