The Apple iPhone comes equipped with a Maps application for looking up nearby destinations and a Compass app for figuring out which way you are facing, but does not offer any default method for determining your elevation. The phone is capable of gathering correct elevation data, however, and can do so with the help of third-party applications. As is the case with most iPhone tasks, when it comes to finding your elevation, "There's an app for that."
Open the Safari app on your iPhone.
Type "altitude.iphonemarks.com" into the browser bar. Tap "Go" to proceed.
Wait while the site loads your altitude information based on your iPhone's GPS coordinates. You can also download the Altitude app from the App Store, which performs the same task and was created by the same team.
Via Elevation Pro
Download and install Elevation Pro from the iPhone's App Store.
Touch the Elevation Pro icon to open the application.
Touch "OK" when the app requests your location information.
Wait for the app to load your current elevation.
Via Elevation for Real
Download and install the Elevation for Real app.
Touch the app's icon to open it. Allow it to use your location data by touching "OK" on the pop-up.
Give the application a few seconds to calculate your current elevation.
Apps and the iPhone can give you an estimate of your elevation but are not the same as professional altitude tools.
Information in this article applies to iOS 6.1. It may vary slightly or significantly with other versions or products.