These are the most common sizes you'll come across, always measured diagonally across the screen. The following range from most common to least, and include different aspect ratios and resolutions that are often used at that size. 27-inch: This size has become the standard, offering enough screen size without overtaking your desk or stretching out the pixels too much at 1080p. 34-inch: Curved, ultrawide monitors with a 21:9 aspect ratio and 34-inch screen size used to be odd, but these days, they've become an alternative to using two 27-inch screens. There are other outliers, such as the absurd 49-inch, 32:9 behemoths, known as “super ultrawide” monitors, or 16-inch portable monitors that are meant to pair with your laptop.