How to Delete Old iCloud Backups on iPhone & iPad (in iOS 9, iOS 8, iOS 7)
Backing up a device to iCloud is highly recommended, but sometimes users get a new iPhone or iPad and they have old backups laying around in their iCloud account, which may not do much and just end up taking space. Assuming you have no use for the old backups anymore, you can easily delete them from iCloud and free up some iCloud space this way.