While we’ve seen a number of possible “iPhone 4S” parts based on the iPhone 4 design in recent weeks, the design of the iPhone 5 has remained unclear with little concrete evidence of the device’s design having yet surfaced. The first claim of a radical redesign surfaced back in April, suggesting that the iPhone 5 would adopt a “teardrop” form factor tapering in thickness from top to bottom.

@TatWZA @Yungjohnnybravo 

By late July, a purported design document for the iPhone 5 surfaced and began to make its way to third-party case manufacturers, who apparently placed enough faith in its accuracy to begin making cases based on the design.

Based on that same design document, we commissioned a set of renderings in an attempt to get an idea of what the iPhone 5 might look like. Our designer took measurements of this imaginary device using the dock port as a standard measurement and produced the document shown above. Based on that extrapolation, the iPhone 5 design should have had dimensions of 4.33″ x 2.36″, suggesting a shorter but only slightly wider design. In comparison, the iPhone 4 dimensions are 4.5″ x 2.31″.

What we can’t explain, however, is that the actual third-party cases circulating are significantly longer and wider than what the design document would have suggested.

Measurements

We ordered a pair of these third-party iPhone 5 cases, confirming they are available for public sale and subjecting them to a series of measurements.

While accurate measurements were difficult to achieve due to open ends and overhangs on the sides of the case, we estimate the size of the phone at approximately 4.7″ x 2.6″. Measuring the expected thickness of the device is more challenging given uncertainty about exactly how the case snaps onto it along the sides, but the device certainly appears to be below .30″ at its thickest and tapering by approximately .065″ from top to bottom.

The following images show an iPhone 4 inside this iPhone 5 case with substantial room on all sides, illustrating the increased size of the iPhone 5. The much thinner profile of the iPhone 5 compared to the iPhone 4 is also visible in a side shot.

[Mac Rumors]