How to delete a subscribed calendar on iOS11
I tried to answer a question on another thread (How to delete subscribed calendars on iOS 10? ) but it won't let me! So, having come here to find the answer (but failing and googling further), I thought I'd answer it here in case others are still wondering.
The issue is that most of the advice for deleting subscribed calendars tells you to go to settings -> calendar -> accounts, but this doesn't exist in iOS11. The answer is to go to settings -> accounts & passwords -> subscribed calendars. From there, you do have the option to delete the calendar. Hope this helps someone!
iPhone 6s, iOS 11.1