There are certain occasions when you may wish to know the exact size of your computer's monitor. Whether you are looking to find a new monitor of a similar or larger size or you are purchasing a screen protector or filter, it is imperative that you understand how to measure your computer screen properly. It's an easy and quick process.
Pull out the measuring tape and hold the lead edge to the top left corner of your monitor's screen. Be sure you are only measuring the viewable area. The frame is not included in this measurement.
Slide the measuring tape straight across the center of the screen to the bottom right corner.
Check the measurement on the tape to see how many inches your monitor is across the diagonal.