iPhone 5 focal length math

[DirtySocks85]

So I'm fairly new to photography, and I expect that my math could be a bit off, but I was trying to figure out the focal length (per sensor size) on the iPhone 5 and this is what I came up with.

So the listed focal length in the EXIF data on my iPhone photos is 4.13mm.

I believe I read somewhere that the crop factor of the iPhone sensor on the 4S and the 5 is 7.5 (if this info is wrong it throw off everything else).

So if I'm understanding how the focal length math works, this is essentially the same angle as about 30mm on a full frame sensor or 50mm on a 1.6 crop factor sensor (such as most entry level DSLRs).

Would this be correct? This is mostly just a thought exercise, but would be good information to keep in mind while shooting with my iPhone.