A note on screen sizes and aspect ratios

The diagonal is a misleading measure of screen size when comparing the size of screens with different aspect ratio.

For example, if you have a 19 inch screen with a 5:4 aspect ratio and you want to switch to a widescreen monitor with at least the same screen height, how big should the diagonal be? Using the table below, you can find out.

The table shows width×height=area for some common screen sizes and aspect ratios.

5:44:316:1016:9
1713.3×10.6=141.013.6×10.2=138.714.4×9.0=129.914.8×8.3=123.5
1814.1×11.2=158.014.4×10.8=155.515.3×9.5=145.615.7×8.8=138.4
1914.8×11.9=176.115.2×11.4=173.316.1×10.1=162.216.6×9.3=154.3
2015.6×12.5=195.116.0×12.0=192.017.0×10.6=179.817.4×9.8=170.9
2116.4×13.1=215.116.8×12.6=211.717.8×11.1=198.218.3×10.3=188.4
2217.2×13.7=236.117.6×13.2=232.318.7×11.7=217.519.2×10.8=206.8
2318.0×14.4=258.018.4×13.8=253.919.5×12.2=237.820.0×11.3=226.0
2418.7×15.0=281.019.2×14.4=276.520.4×12.7=258.920.9×11.8=246.1
2519.5×15.6=304.920.0×15.0=300.021.2×13.2=280.921.8×12.3=267.1
2620.3×16.2=329.820.8×15.6=324.522.0×13.8=303.822.7×12.7=288.9
2721.1×16.9=355.621.6×16.2=349.922.9×14.3=327.623.5×13.2=311.5
2821.9×17.5=382.422.4×16.8=376.323.7×14.8=352.424.4×13.7=335.0
3225.0×20.0=499.525.6×19.2=491.527.1×17.0=460.227.9×15.7=437.6