All the help I find is for the opposite direction. I need my Outlook.com calendar to show up in my Google calendar, as the events I create in my windows phone don't sync to my main Google calendar.
I am not using the Outlook windows application.
I attempted to share the calendar from Outlook.com to my gmail address, but get an error:
Sorry, this invitation isn't valid anymore. The sender may have taken away your permission, or you may have already declined this invitation. If you'd like to see this calendar, ask its owner to share it with you again.
If there is an alternative solution that accomplishes the result I want (my Outlook.com events showing up in Google calendar) that would be OK.