PPI Calculator

Calculates pixels per inch using either auto detected or user inputted values

Have a friend with an iDevice who keeps bragging about his "retina display"? Well then this (most likely) is the application for you. Use it to show him that your screen is more pixel dense than his marketing gimmick.

And if you don't have such a friend you can use it to compare resolution/size dynamics of various screens:

-Compare phone/tablet screens by just installing it on a phone and clicking auto detect.

-Enter values manually if you are buying TVs or monitors.