How do I adjust the resolution of my Retina display?
Your MacBook Pro with Retina display has 2880 x 1800 pixels and starts up in its native Retina mode, which is the recommended resolution for use on this computer.

If you need to adjust the display resolution, choose System Preferences from the Apple (?) menu. The Retina display offers scaled resolutions that allow you to have text and objects appear larger on screen, or to make them appear smaller which provides more space on screen.