One of the most useful Apple Watch features is being able to locate your misplaced iPhone. To ping your iPhone, swipe up on the Apple Watch display to access the Settings glance, then tap Ping iPhone. This will only work if your iPhone is in range of your Apple Watch. When the two devices are not connected to the same Wi-Fi signal the range is about 330 feet (100 meters) for a Bluetooth connection.
How do I find my iPhone with my Apple Watch?