Screen size. There has been a lot of talk about the new iPhones screen size, the iPhone with a 4.7 screen seems all but confirmed, while a larger iPhone with a 5.5 screen has been somewhat quietly rumoured. I sketched it out, and was suprised at how much of a jump 4.7 really is. (I know combining metric and imperial measurements on a drawing is a big no no, but metric is just easier to work with.) Going from a 4 screen to a 4.7 screen may initially seem like a trivial jump, but in reality it offers a 40% increase in screen real estate. Quite significant. (From 4400mm² to 6136mm²) Going all the way to a 5.5 screen, you almost double the screen real estate! (From 4400² to 8228mm²) So even though we are talking about small increases on paper, the size increases are actual very significant. Screen resolution. When Apple revealed the iPhone 4 in 2010, they boldly said, When the PPI gets over 300, you can't see the pixels when you hold the device 12 away from your face, the normal usage distance. It worked out nicely then, that the iPhone 4 and subsequent iPhones have a PPI of 326. So having a PPI less than 300 is a no go for Apple, if they want to advertise the iPhone 6 having a retina display, which they will want to. (The iPad Air has a PPI of 264, however Apple state that we hold our iPads further away from our eyes, about 15, and therefore is still a retina display.) At a resoultion of 1136 X 640 on a 4.7 screen, the PPI falls to 278. Slightly below the 300 target Apple have set themselves. And when you apply this resolution to a 5.5 screen it dwindles down to 237 PPI, not very desirable in 2014. So the resolution has to increase. Recent Apple history tells us, that when they inscrease screen resolution, they double the X and double the Y, offering 4 times the pixels. Quadrupling the screen resolution has huge benifits to users and developers. Apps can be double sized to fill the whole screen, so in most cases a user might not even notice if an app has been updated or not. I think the next iPhone will have a resolution of 2272 X 1280. Therefore the 4.7 iPhone will have 555 PPI, and the 5.5 iPhone will have 474 PPI. This may seem overkill, but it isn't unheard of in 2014. (2K screens are becoming a 'thing' and The Samsung Galaxy S5 Prime has 576 PPI.) When Apple introduced the iPhone 4 in 2010, a screen in a consumer product having 326 PPI was an insane thought. And I think Apple will make a similar insane jump this year. It's a huge leap, however it's benifits are obvious. Once again, Apple will be (slightly) ahead of the competition when it comes to screen PPI, but more than that, they won't have to change it for another 4 years at least, maybe even longer. This means, developers don't have to worry about catering for different screen resolutions, different app layouts, different asset sizes etc. Now come next month, I may well be wrong, but if Apple release a screen that isn't 2272 X 1280, you can rest assured that it wasn't their first choice.