Much has already been written about a larger "iPhone 6". 4.7 and 5.5-inch displays have been rumored, but for the first time we have what looks like concrete information, via 9to5mac. Apple’s iPhone 6 will most likely use a resolution of 1704x960 pixels. Here is how it will work.

A larger iPhone 6 
A larger iPhone has been rumored for a long time and some dubious plastic dummy iPhones are current floating around in Asia. The last time Apple increased the display size was with iPhone 5 to a 4-inch display, and the first change to resolution came with iPhone 4. It is worth dwelling on this for a moment. 

Apple moved from 320x480 to 640x960 pixels when they introduced the Retina display in iPhone 4, but instead of making icons and apps appear smaller, “2X” scaling was introduced. In other words; icons and apps remained unchanged in size, but looked far more detailed. 

Apple chose a different approach when the iPhone 5 was launched. They changed the physical aspect ratio to 16:9 – the same as on TVs – on a larger 4-inch display and added more pixels in the vertical direction, bumping resolution up to 640x1136 pixels. iPhone 5 was the first iPhone to include more display real estate for apps.

When iPhone 6 launches later this year it appears that we have to look back to iPhone 4 – and not iPhone 5 – to understand the change in display resolution.


The size of a potential 4,7” iPhone next to iPhone 5. Picture credit: 9to5mac

Not like iPhone 5
According to sources, iPhone 6 will feature a resolution of 960x1704 pixels. This may seem like a strange number, but there is a method to the madness. It represents a new "3X" scaling level. 

Scaling:
1X = 320x568 (as apps are created) 
2X = 640x1136 (on iPhone 5, 5C and 5S) 
3X = 960x1704 (new resolution for iPhone 6) 

Notice how 320x2 equals 640 and 320x3 equals 960 and so on. 

In other words, it means that the display of iPhone 5 will become larger at 4.7-inches, but that the user interface will remain unchanged. There will be no additional app rows and there will be no top/bottom black bars inside apps. The 4.7-inch display will also maintain the same 16:9 aspect ratio and become both wider and taller.

It also means that the display will have a higher pixel density. If it indeed turns out to be a 4.7-inch display, pixel density will reach 416 ppi, up from 326 ppi today. App designers will not have to change the format or user interface of an app, but they will have to update graphics with 3X images. 

Time will tell what Apple decides to do, but 9to5mac’s scenario certainly appears plausible. It is not unlikely that Apple will follow the same route to a larger iPad – higher resolution with 3X scaling.

- Source: 9to5mac