Google Product Forums
Re: How do I sync multiple calendars to my iPhone calendar?
zdravko.g Jun 17, 2012 2:10 AM
Posted in group: Google Mobile Help Forum

Categories: Apple Devices : Other Google Products :

 I had many problems with syncing more then one calendar too. https://www.google.com/calendar/iphoneselect didn't helped me. I have found why only some of people have trouble to sync many calendars with iPhone. That's cause they have ( or had ) more then one device. I have one, but i have replaced it in service before time, so google thinks i have two of them. So what did the trick for me.

All links must to be open from the iPhone!

1. https://www.google.com/calendar/iphoneselect  at this link i enabled all calendars i need
2. At iPhone , Settings -> Mail -> Gmail Exchange ->  disabled then re-enabled Calendars 
3. Still only ONE calendar in iCallendar app in iPhone
4. Then i hardly found this page https://m.google.com/sync/settings/iconfig/welcome?source=mobileproducts&hl=en , where you need to select each device and again select additional calendars.
5. Go again at iCalendar, you have to have all that calendars there!

  Good luck !