What is a pixel? And how are pixels calculated?

What is a Pixel?

Zoom in far enough on your screen and eventually you鈥檒l see small squares of various colors. Each individual square is called a pixel.

Pixel is derived from the phrase picture elements. Each element of the picture serves as a building block in the screen鈥檚 grid. Each pixel has a unique location indicated by a set of coordinates. It also has the capacity to broadcast millions of colors!

What You Need to Know About Pixels

The number of pixels in an image or display determines how the image looks.

Screens with high-density pixel grids make it impossible to detect individual points with the naked eye resulting in a sharp and crisp display.

Screens with lower densities produce grainy and difficult-to-make-out images. But sometimes pixelation is exactly what your design needs!

Modern designers need a comprehensive understanding of this topic. To get you started here are 5 things you need to know about pixels.

1. How to Calculate Pixels

Display resolution indicates how many pixels are contained in a screen. So a 1080x1920 display is just a grid that鈥檚 1080 pixels tall and 1920 pixels wide. To calculate the number of pixels in a display multiply the height of the grid by the width.

In the case of a 1080x1920 display there鈥檚 a total of 2073600 pixels within the grid!

2. How Pixels Create Colors

Each individual point blends with those around it to create a smooth transition of color. Think of it like an absurdly detailed impressionist painting. The more colors each point can display the more natural and crisp the image looks.

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The number of bits used to represent a pixel determines how many colors it can display.

So an 8-bit pixel only allows for 256 colors while a 24-bit pixel displays 16777216 colors!

3. How Pixels Determine Display Resolution

Resolution is measured in PPI (pixels per inch) so it鈥檚 a measurement of the pixel density in a given image or display. Both the PPI and the size of the image can affect the resolution.

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If the pixel density is too low it can cause some real problems...

4. The Importance of Pixel Density

Pixel density helps determine the clarity of an image.

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The pixel density of an image must complement the size of that image. If for example you鈥檙e displaying a large image you鈥檒l need a higher PPI to avoid pixalation.

5. The Importance of Pixel Depth

Pixel depth describes the amount of data that can be stored in each individual square. The number of bits that represent a pixel determine how many colors it can display.

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The more colors a pixel can display the better the tone of the photo and the more lifelike it will look. A quality image is not just determined by the number of pixels in the image but also the depth of those pixels.

How to Utilize Pixels in Modern Design

Understanding pixels and how to use them is a must for today鈥檚 designers. It鈥檚 the building blocks for everything we see digitally. Here are a few times you鈥檒l use them:

1. When You鈥檙e Designing for Specific Devices

You need to understand both screen specs and CSS pixels to create brilliant device-specific designs. This enables you to make smart decisions for the project.

The resolution and PPI of a device are almost always provided by the manufacturer. You can also find direct device comparisons on third-party websites.

However in design CSS pixels are just as important. They鈥檙e abstract (but still related) units used by designers that don鈥檛 directly correspond with regular pixels. In modern devices with high-density screens there are often two device pixels per CSS pixel.

2. When You鈥檙e Creating a Responsive Website

In today鈥檚 world you must have a responsive website. Very few people if any will stick around on your outdated website -- especially if they鈥檙e on a mobile device. Responsive websites are all about looking great at different sizes and resolutions.

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Each screen size will present your website in a slightly different way. You鈥檒l notice content is getting scaled down and broken up differently. Small images may get pixelated as a result. Make sure to run tests at all common sizes and resolutions to make sure the site is actually as usable鈥攁cross every device.

3. When You鈥檙e Trying to Improve Image Quality

Increasing an image鈥檚 resolution or shrinking the size can help increase PPI for a grainy image. Displaying fewer pixels鈥攁nd more data for each pixel鈥攃an help enhance the color tone and weight of an image. Size pixel density pixel depth and color are all settings that can drastically change the quality of a photo.

Related Terms

If you enjoyed this guide continue exploring with these related terms.A. Pixelation: When pixels are stretched beyond their limit this phenomenon can cause real problems.B. Gradient: When working with colors it鈥檚 important to know how they can blend to create interesting effects.