The difference between a 4.7-inch display and 6.1-inches seems like a lot, and in terms of screen space it is. But the phones themselves? There’s not a huge amount of difference between them all.

In a great “Doing the math” post, Chris Rawson at TUAW outlines the single reason why the next iPhone won’t get the rumored 4-inch screen: Apple could work around that issue by slightly increasing the ...