iCloud: Set up Find My iPhone
Set up an iOS device
On your device’s Home screen, tap Settings, then tap iCloud.
If you’re asked to sign in, enter your Apple ID. If you don’t have one, tap Create a new Apple ID, then follow the instructions.
If Find My iPhone (or Find My iPad or Find My iPod) is turned off, tap Find My iPhone, then tap to turn it on.
Tap to turn on Send Last Location.
If your device is lost or stolen and its battery charge level becomes critically low, its location is sent to Apple automatically. When you use Find My iPhone to locate that device, you see where it was before its battery ran out of charge.
Set up a Mac
On your Mac, choose Apple menu > System Preferences, then click iCloud.
If you’re asked to sign in, enter your Apple ID. If you don’t have one, click Create new Apple ID, then follow the instructions.
If Find My Mac is turned off, select it to turn it on.For added security, make sure your user account requires a password and that automatic login is turned off in Users & Groups preferences.
Share your location with your family members
If you’re part of a Family Sharing family, you can use Find My iPhone to help find your family members’ iOS devices (iOS 8 or later) and Mac computers (OS X v10.10 or later). First, each family member must set up their devices and computers to share their locations with other family members.
On an iOS device: Go to Settings > iCloud > Share My Location.
On a Mac: Open iCloud preferences, click Manage Family Sharing, then select family members one at a time.
For more information, see the Apple Support article Family Sharing.
When you set up Find My iPhone, Activation Lock is turned on automatically. Activation Lock makes it harder for anyone to use or sell your iPhone, iPad, or iPod touch if it’s ever lost or stolen. For more information, see the Apple Support article Find My iPhone Activation Lock.
If you’re having trouble with Find My iPhone, see the Apple Support article Troubleshooting Find My iPhone, iPad, iPod touch, or Mac.