What is 720p, 1080p, 1440p, 2K, 4K, 8K? Popular Screen Resolutions Explained & Compared

• Learn how a display resolution is measured and what is the meaning of the most popular terms in the industry.
• Screen resolution is one of the most important specifications of a monitor or TV. For sure it’s the most popular.
• There are a few very popular terms, such as 720p, 1080p, and 4K, but most people don’t really know what lies behind these acronyms.

For a long time, TV and PC resolutions were stuck at very low pixel counts. Only recently the number of pixels on screens has increased dramatically, which of course means a much better viewing experience and finer details.

This means it’s important to know what terms like 1080p, 2K, and 4K represent so that when it comes to making a purchase decision you pick the right product.

How is Screen Resolution Measured?

A digital screen is made of pixels, arranged in rows and columns, just like a matrix. When you speak about the physical resolution you’re talking about the number of physical (individual) pixels that form the screen panel.

Resolution in pixels is expressed in horizontal resolution x vertical resolution, basically, the number of columns x rows a screen has.

It’s simple, really. The problem is that most people can’t remember things like 7680 x 4320. That’s why the industry invented terms that describe these resolutions.

The Most Important Terms Used to Describe Resolutions

This is where the real problem comes from: the lack of a standard when describing resolutions. Here are the most common ways to describe resolutions. Prepare for something completely unintuitive.

Resolutions ending with a “p” – 720p, 1080p, 2160p

Correspond to the number of horizontal lines (rows). P stands for progressive – rows are drawn in an ordered fashion on the screen.

Resolutions ending with an “i”- 1080i

Describes the number of horizontal rows, but lets you know the rows are not drawn on the screen in ascending order (it’s called interlaced). First, come the odd rows then the even ones.

This is mostly used for TV broadcasts in order to reduce the required bandwidth for transmitting the data. It’s easy to spot interlacing because the image has a slight flicker, which for sensitive eyes can be very annoying.

Resolutions ending with a “k” – 2K, 4K, 8K

Correspond to the number of vertical columns, but might not match the physical resolution exactly: 2K screen resolution is not equal to 1920 and 4K screen resolution is not equal to 3840. Isn’t tech amazingly confusing sometimes?

Resolution terms that use words – SD, HD, Ultra HD

SD defines pre-high-definition screens, aka Standard Definition, while HD Ready, Full HD, and Ultra HD (UHD) describe increasingly higher resolution panels, aka High Definition. SD < HD Ready < Full HD < UHD < 8K.

Comparison Table of Popular Screen Resolutions

As with many tech terms, screen resolutions make no sense, unless you know what hides behind each term. Here’s a table to get you started with the most popular resolutions and their corresponding number of pixels.

You may have noticed I’ve added two more columns:

• Aspect ratio – it describes how large the width of the screen is compared to its height. 4:3 is rarely used anymore, as people prefer wide screens, with a 16:9 aspect ratio, which are more cinematic. 16:10 screens that feature more vertical space are making a comeback in laptops, and hopefully, in desktop monitors, where they’re more productive.
• Megapixels – it’s another term used to describe the total number of pixels on a screen (made popular by digital camera sensor sizes). You’d be amazed to find out that in less than 20 years the pixel density increased by more than 80 times!

Do I Need to Use the Maximum Screen Resolution?

As you may find out in Windows and other operating systems, you can choose a lower resolution for your screen. This is not really optimal, not at all actually, since the image will be blurrier. It’s not what you’ve paid for!

If you have trouble with tiny text and other elements shown on-screen find the scaling option and crank that up a bit. It will enlarge the graphics while using all the available pixels so that everything looks crisp, for those with better vision, at least.

Resolution alone doesn’t give you a sense of how crisp a screen is. You have to account for screen size too and how close you’re sitting. So pixel density comes to play. For phones, a density above 300 ppi (pixels per inch) means a retina display. Basically, a normal person with good vision can’t distinguish the individual pixels of such a screen.

I do hope this article shed a light on the most popular screen resolutions and their meaning. If you have any questions feel free to ask them in the comments. I’d be happy to answer.

Ionuț-Alexandru Popa

I'm a writer and Editor-in-Chief at BinaryFork. I am passionate about technology, science, space exploration, and movies. I started writing about tech more than 20 years ago, after graduating in Computer Science.