Yep, that's because it's 960px in CSS pixels, which are at 96dpi. Your monitor a...

jahewson on Nov 4, 2013 | parent | context | favorite | on: In CSS, “px” is not an angular measurement and it ...

Yep, that's because it's 960px in CSS pixels, which are at 96dpi. Your monitor also has it's own physical dpi so you can't just measure the length of a line on the screen to infer the OS's dpi.