Mobile phone screen size is measured by the length of the screen's diagonal, in inches.
For example, a 5.8-inch screen means its diagonal is 5.8 inches. 1 inch = 2.54 centimeters (cm), 5.8 inches = 14.732 cm, so the diagonal is 14.732 cm. Therefore, all screens with a diagonal of 14.732 cm are 5.8-inch screens.
Because screen ratios are not fixed, common ratios are 4:3 and 16:9, the length and width are not fixed. For example, the iPhone X has a 5.8-inch screen, but its actual weight and size are:
Screen size consists of two parts: physical size and display resolution.
1. Physical size refers to the actual size of the screen. A large screen must also have a high resolution, which means how many pixels can be displayed at that size. The more pixels displayed, the greater the potential for visual display.
Two monitors have screens of roughly the same size, yet one can only display two lines of Chinese characters, while the other can display five. Ignoring the difference in font size, the key difference lies in the screen resolution. The latter has a higher resolution, naturally allowing it to display more lines of Chinese characters at the same font size. Similarly, higher resolution results in clearer images, smoother lines, and a more realistic representation of scenery.
2. Screen resolution is calculated by dividing the number of LCD pixels (in dots) by the screen area. This metric is the most significant factor determining image quality. Therefore, when choosing a monitor, in addition to considering the color depth the screen can display, screen resolution is also a crucial factor.