Screen resolution – what is it and which is better

Most manufacturers list PPI on screen specifications. But you can calculate the indicator yourself. To do this, you need to know the resolution and screen diagonal in inches. Use the formula:

Wp is the number of horizontal pixels, Hp is the number of vertical pixels, and dp is the diagonal resolution. It remains only to divide the resulting value by the diagonal in inches:

For example, we have a monitor with a resolution of 1920 × 1080 and a diagonal of 24 inches. Then, using the formula, we define dp:

The specs shown are for the Acer KA242Ybi monitor, and if you examine its parameters, you will find that the PPI is indeed 93 pixels per inch.

Where did 2K, 4K, 8K come from?
There are over 30 different resolution formats, ranging from QVGA 240×320 px to stunning 10K at 10240 × 5760 px. You can explore the most common screen resolutions below.

Attentive readers will have noticed that the table contains a couple of different lines labeled 2K. The situation is similar with 4K resolution. In fact, there are several different resolutions for 4K format at once:

Horizontally, almost all of them are close to four thousand pixels, but the vertical resolution directly depends on the aspect ratio. True 4K in this case is called DCI 4K, used in cinematography. However, this aspect ratio was not suitable for monitors and TVs. That is why the Consumer Electronics Association (CEA) in 2012 approved a single 4K format for digital electronics, which was called Ultra HD 4K.









This means, if 4K is indicated on the box of a monitor or TV, then according to the adopted specification it will have a resolution of 3840×2160.

Which ratio is better depends directly on the format of the film or game. There are usually no problems with games, since they easily adapt to different formats, but when watching a movie of an unsuitable resolution, black lines may appear at the edges of the screen.

The most popular aspect ratios for which most of the multimedia content is adapted are 16:10 and 16: 9.

About smartphone screen resolutions
With mobile electronics, everything is much more complicated, since the variety of form factors is much greater. If we consider the line of smartphones from Apple, then the situation is as follows:

The developers managed to achieve FullHD resolution of 1920 × 1080 with a 5.5-inch diagonal, and the maximum 2688×1242 is available on 6.5-inch smartphones. Conditionally, it can be called close to 2K.

It is even more difficult for Android gadgets as there are hundreds of different models on the market. Conventionally, a general classification can be distinguished from five categories:

Smartphones with 4K displays are also available. For example, the Xperia XZ2 Premium features a 5.8-inch IPS display with a resolution of 3840×2160. In fact, this is the “classic TV” standard Ultra HD 4K, and the pixel density reaches an impressive 765 ppi. If you expect unprecedented clarity, you can be disappointed. The problem is that it is almost impossible to tell the difference between FHD + and 4K, especially in the framework of displays of 5-6 inches.

When choosing a monitor for gaming, coordinate the resolution with the hardware. You should not chase 2K and 4K monitors if you have a weak video card and processor. It is better to take TVs for watching movies with a resolution of 2K and an aspect ratio of 16: 9 or 16:10 in order to fully enjoy the detailed picture.

When buying a smartphone, the determining factor is the pixel density per inch, since the display is always in front of your eyes and the “grain” is the easiest to see. Look for smartphones with 300-450 ppi. Your eyes will no longer distinguish high density.