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# How to calculate the density of pixels per inch of a screen?

When we are in the search for mobile phones we always resort to looking for their characteristic or technical specifications. Among this compendium of data, the size of the screen, as well as the resolution, always stands out. But because in most of this data the pixel density does not appear. This article will show you how to calculate the density of pixels per inch of a screen? This information is important to know and not only for mobile phones , this also applies to Laptop screens, monitors, TV. Since with this data we can know if the screen will offer us a good image quality. So, if we cannot find this data or it is very difficult for us to invest time in it, we can learn to calculate it in a very simple way.

In a previous article we showed you how you could know the size in inches or pixels has the screen of my laptop in Windows or Mac. But in this case we will teach you how to calculate the density of pixels per inch of a screen? But starting from two data if you must have and that is always offered by the manufacturer and that is the size of the screen and the resolution.

## How to calculate the density of pixels per inch of a screen?

Unfortunately, these are data that tend to confuse users a bit, since they think that this data separately will offer them a better image quality and it is not. For example, a screen that has a higher resolution than another screen. It does not make it better in terms of the image, since another data must be taken into account and that is the size of the screen.

But before starting to make calculations we are going to clear a question and it is of course that it means pixel density . And this is not more than the amount of pixels that we can find in an inch of said screen. The greater the number of pixels that we can find per inch, the better the image that that screen has.

And it is denoted by PPI, Pixel Per Inc. and means in Spanish Pixel Per Inches, so this value is very important to know the sharpness of the screen image. Ok then, taking this knowledge into account, we will go on to look for two other pieces of information that are important to know the pixel density and that is the screen size and the resolution.

## Calculation of pixel density

Now, with the data that we can obtain from the manufacturer, we can realize that it offers us the size of the screen diagonally. In other words, if a screen is 32 inches, it will be measured from one corner to the other corner in a diagonal direction. And the resolution is the horizontal and vertical measurement of the screen, but this is in Pixels.

So we have the number of pixels in a vertical line and the number of pixels in a horizontal line. And we have the screen diagonal measured in inches, so how do we solve this riddle. Well, applying the well-known and feared Pythagorean theorem, if that’s how you hear it and in the following example we will illustrate it.

This theorem tells us that the hypotenuse will be equal to the square root of the square of the opposite leg plus the square of the adjacent leg. Where the horizontal and vertical pixels are the legs and the hypotenuse is the diagonal. So if we apply this theorem to a 5-inch Galaxy S4 phone we will have that one of its legs is 1920 pixels and the other 1080 pixels.

This will give us that the hypotenuse or its diagonal which is 5 inches has 2202.9 pixels, having this data we can solve the story question would be the pixel density of this screen. We just need to divide the length of pixels by the length of inches. In our case it would be 2202.9 pixels between 5 inches and it will give us 440.59 PPI as a result. In this way you can obtain this important data and make comparisons between different screens to know which one will have the best image quality . From this we finish with this instructive guide that could teach you how to calculate the density of pixels per inch of a screen.