I found the data sheet here which states these numbers ...
13.3-inch (diagonal) LED-backlit display with IPS technology; 2560-by-1600 native resolution at 227 pixels per inch with support for millions of colors
Supported scaled resolutions: 1680 by 1050 1440 by 900 1024 by 640
When I actually measure the width I get 1440 pixels.
I do this by using a grid image that is 100px wide as a background for my website in Google Chrome.
Just curious to how I have 2560 Native and how this is scaled to 1440.
1440 just happens to be
1024 + 256 + 128 + 32