How To Sync Mail, Contacts & Calendars From Android To iOS 

If you ever thought of switching from Android to iPhone or to use the iPhone or iPad Mini as a secondary device, then you certainly would want to sync your mail, contacts and calendar information on both devices. With the Google account used on your Android device to backup these information, a final backup will ensure that everything you need will be properly synced to your iOS device.
To get all your important mail and schedules paired up in your Android and iOS devices, there just 2 things you need to do: sync your Mail and Calendar, and sync your Contacts. All you have to do is sign in to your Google account, twice.

How To Sync Mail and Calendar

First, go to Settings > Mail, Contacts, Calendars > Add Account.

Select Gmail and key in your name, email address, password and description and tap on Next and then Save. Now when you go to the Mail or Calendar app on your iPhone, you should have all the necessary information synced.

How To Sync Contacts

To sync contacts, you’ll have to go to go to Settings > Mail, Contacts, Calendars > Add Account > Other.

Tap on Add CardDAV Account and on the next screen, under Server, type in ‘google.com’, fill in your full email address for User Name, then enter your password and tap on Save.
Now all your Google contacts from your account will be available on the Contacts app of the iPhone.