The screen's aspect ratio must be known to determine the dimensions of a 20-inch television. For example, most latest television manufacturers make TVs with a 16: 9 aspect ratio. It indicates that if we divide the screen's height by width, the result equals 16: 9, or roughly 1.78. The properties of the television are used to determine the aspect ratio. For example, the aspect ratio of modern televisions with HD, Full HD, and Ultra HD (sometimes referred to as UHD or 4K) resolutions is typically 16: 9. The aspect ratio of older TVs with regular SD (Standard Definition) resolution is 4: 3. This kind of format has been replaced by high definition with a 16:9 aspect ratio. The 20 inches refers to the length of the diagonal of the screen. This length is equal to 50.8 centimeters when expressed in centimeters. Assuming a 16:9 aspect ratio, the screen measures 44.3 cm in width and 24.9 cm in height. Before the advent of high-definition screens (HD, Full HD, and Ultra HD) a few years ago, the most prevalent televisions had a 4: 3 aspect ratio. The width, therefore, represented 1.33 times the height. With this aspect ratio, a 20-inch TV would measure 40.6 cm in width and 30.5 cm in height. Even so, it is uncommon to find a television of this sort with a large number of inches today. These measurements solely show the screen's dimensions. Be aware that the frame supporting the screen will result in a modest increase in the TV's overall size. In addition, one must consider the television's depth, which varies based on the model.