How to Know Your Screen Resolution?

WINDOWS

1. Right-click on an empty section of your Windows desktop.
2. Click the "Screen Resolution" option that appears in the list.
3. View the numbers shown next to the "Resolution:" heading on this screen. The first number is the number of horizontal pixels Windows is trying to display. The second number is the number of vertical pixels. If you see a "(Recommended)" label after this number, it is because Windows believes this screen resolution is the best one available to match your monitor or display.
   

MAC

1. First, click the Apple icon in the upper-left corner of the screen, and select “About This Mac.”
2. In the window that pops up, click the “Displays” tab
3. On the next screen, you will see information about the display (or displays) you have built-in or attached to your Mac.
   The screen resolution is the set of numbers listed in parenthesis just after the size of the display. For example, the listing here says “27-Inch (2560 x 1440)” which means that the Mac in this image has a 27-inch display with a 2560 x 1140 pixel resolution.

ANDROID

1. Click Settings.

2. Then click Display.

3. Next, click screen resolution.