Surprisingly, as seen in the above image, though the glass panel in question has the same width as the iPhone 4/4s, it measures 4.07 inches diagonally, or approximately 10.33cm, versus the 3.5-inch display on current iPhones.
Macotakara explains :
If you look at just how long or than the iPhone 4S, is the feeling you move up to the length of the sensor bar from Lacey. However, I think this length is shorter than the liquid crystal display area was expanded.
Watch this video" comparison between iPhone 5 & iPhone 4S: