Set up your iPhone and FaceTime on Mac for phone calls
You can use the FaceTime app on your Mac to make and receive phone calls — including Real-Time Text (RTT) calls — when you set options on your iPhone and Mac. See FaceTime phone call requirements.
Set up your iPhone
On your iPhone, go to Settings > Phone.
Choose one of the following, depending on your carrier.
If you see Wi-Fi Calling: Tap it, then turn on Wi-Fi Calling on This iPhone.
After you turn on Wi-Fi Calling, you may see an Add Wi-Fi Calling For Other Devices button. Tap it to allow calls using your other Apple devices that aren’t on the same Wi-Fi network as your iPhone, or if your phone is off. Otherwise, you can still use your Mac to make phone calls, but your iPhone must be turned on and on the same Wi-Fi network as your Mac.
Note: Only certain phone carriers support Wi-Fi Calling for devices that aren’t on the same Wi-Fi network as your iPhone. See the Apple Support article Make a call with Wi-Fi Calling. You also need iPhone 5s, iPhone 5c or later.
If you see Calls on Other Devices: Tap it, then turn it on.
This option allows calls using your other Apple devices that are on the same Wi-Fi network as your iPhone.
Set up your Mac
If you turn on Wi-Fi Calling on your iPhone, you might be asked to turn on Calls from iPhone on your Mac when you open FaceTime on your Mac. If you don’t get this notification, do the following.
In the FaceTime app
on your Mac, choose FaceTime > Preferences, then click Settings.Select Calls from iPhone.
If you can’t see this option, make sure your Mac meets all the requirements, then open FaceTime preferences again.
If an Upgrade to Wi-Fi Calling button appears, click it, then follow the onscreen instructions.
This button appears if your carrier supports Wi-Fi Calling when your iPhone is turned off or is on a different Wi-Fi network.
If you’re asked to confirm your address for emergency services, click Update Emergency Address. (If you make an emergency call that uses Wi-Fi instead of the mobile network, the address you provide here helps emergency services locate you.) See the Apple Support article Make a call with Wi-Fi Calling.
You can turn off phone calls on your Mac at any time. In the FaceTime app, choose FaceTime > Preferences, click Settings, then deselect Calls from iPhone.