Instructions: Simply select your monitor's resolution, and type in one of the numbers below. All the other numbers will be filled in by the calculator. To recalculate based on a different resolution, click the number you want to keep constant and then select a different resolution. Everything except the last number selected will be recalculated when the resolution is changed.
For example, say you have a 24 inch LCD monitor at a resolution of 1280x1024. Select "1280x1024" from the resolution drop-down, and enter "19" into the diagonal box. To see how big a 16:9 monitor would have to be to have the same height as this monitor, click the height input and then select either the "1600x900" or the "1920x1080" resolution.