Find My iPhone is an application that makes locating an iPhone quick and easy. To use the service on a computer, run through the following steps.
Open the iCloud website at Apple.com in an Internet browser.
Use the same iCloud account that is registered on the Find My iPhone application on the phone. Enter a valid iCloud username and password.
Run the Find My iPhone feature in iCloud.
The map shows all devices running the application belonging to the particular username entered. Online devices are marked with a green dot. Offline devices are marked with a gray dot, which displays that device's last known location. Zoom in on the location by pressing the plus icon, and zoom out by pressing the minus icon. Drag the cursor on the map to move it.
Find My iPhone can only locate devices that are online. If the device is offline but was previously online, the application displays the device's last location for up to 24 hours. If the device was not online during the past 24 hours, request a notification. This feature sends an email as soon as the device goes online.