4K vs. 8K vs. 1080p: TV resolutions explained

tv-resolutions-explianed

Geoffrey Morrison/CNET

When it comes to resolution with TVs and phones, there’s a confusing alphanumeric soup. There’s 8K, 4K, HD, 1080p, UHD and more. You’d be right to assume 8K must be greater than 4K, but is it twice as good? Is the difference even noticeable? And where does 1080p fit into the equation? Resolution isn’t the most important factor when buying a new TV — especially because most TVs are now 4K TVs — but it’s still something to consider. More importantly, knowing what all the numbers really mean can help you feel more confident in your TV choice.

Here’s what you need to know. The short version:

  • 4K almost always means the TV has 3,840×2,160 pixels.
  • UHD stands for “Ultra High Definition,” also known as UltraHD, but basically means 4K.
  • Are most TVs 4K these days? At 50 inches and above, yes.
  • Does 4K mean the picture will be better than my old TV? Not necessarily.
  • If 4K is four times greater than 1080p, does that mean 4K is 4320p? No.
  • Is 8K worth worrying about? No.

Still have questions? Let’s start with the basics.

What is resolution?

Resolution, in terms of TV hardware, refers to the number of pixels that compose the picture on the TV. A single pixel, or discrete picture element, consists of a tiny dot on the screen. 

There are numerous resolutions found on flat-panel TVs. Older TVs, and many 32-inch models sold today, have a million or so pixels (720p). More recent and slightly larger TVs (typically 49 inches and smaller) have a little over 2 million pixels (1080p). Even newer and bigger TVs (typically 50 inches and above, although numerous smaller sizes too) have 8 million (for 4K Ultra HD). And the newest, largest and most ridiculously expensive TVs have over 33 million pixels (8K). You’ll have to look very closely, or whip out a magnifying glass, to discern each one.

015-lg-oled-tv-8k15

Here Senior Managing Editor David Katzmaier counts every pixel on an 8K TV.


Sarah Tew/CNET

Resolution is one of the most common specifications used to sell TVs, partly because “4K” and “8K” sound really high-tech and impressive. However, resolution is not the most important ingredient in picture quality. Just because a TV has higher resolution than another, doesn’t always mean it looks better. It might, but not always, and for reasons that have little to do with resolution. A TV with better high dynamic range (HDR) performance, a better overall contrast ratio or better color will look better than one that just has more pixels.

That said, it’s still worth understanding the various resolutions used by TV makers and others. Here’s a bit more, ahem, detail.

Select large-screen resolutions

Resolution name Horizontal x vertical pixels Other names Devices
10K 10,240×5,760 or 4,320 None No consumer products
8K 7,680×4,320 8K UHD TVs
“Cinema” 4K 4,096x[unspecified] 4K Some projectors
UHD 3,840×2,160 4K, Ultra HD, Ultra-High Definition TVs, monitors, projectors
2K 2,048x[unspecified] None Some cinema projectors
WUXGA 1,920×1,200 Widescreen Ultra Extended Graphics Array Monitors, projectors
1080p 1,920×1,080 Full HD, FHD, HD, High Definition TVs, monitors, projectors
720p 1,280×720 HD, High Definition TVs

8K and 4K (Ultra HD)

When it comes to TVs, 4K and Ultra HD (or UHD) are referring to the same resolution. Those TVs, along with Ultra HD Blu-ray, and nearly all UHD streaming content from Netflix, Amazon and others, is 3,840×2,160 resolution.

One potential source of confusion is that 4K means something different whether you’re talking about a TV in your home, or a projector in a theater. Technically, “4K” means a horizontal resolution of 4,096 pixels. This is the resolution set forth by the Digital Cinema Initiatives. Because movies vary in aspect ratio, which refers to the exact shape of the rectangle of screen, no vertical resolution is specified.

So Ultra HD TVs aren’t technically “4K” by the specifications of DCI, but common parlance has usurped the term so “4K” TVs are 4K TVs even though their resolution is 3,840×2,160. Most companies just say both: Ultra HD 4K.

This shows the relative number of pixels in each of the major resolution formats. Not actual size of course; this is a chart not a visual representation (though it is to scale if you click on it).

From largest to smallest: 8K (tangerine), 4K Cinema in 1.78:1 aspect ratio (black); Ultra HD (white); 2K Cinema in 1.78:1 aspect ratio (green); Full HD 1080p (red); 720p (blue).


Geoffrey Morrison/CNET

8K follows the same logic. If you’re talking about TVs, it’s twice the horizontal and vertical resolution of 4K TVs: 7,680×4,320. This isn’t a cinema resolution yet, at least not outside of the experimental stage. There are a handful of 8K TVs on the market, but it’s going to be many years before this resolution is common. 

To get the most out of your 4K TV, you need 4K content. Fortunately, there’s 4K content everywhere. Most of the major streaming services, like Netflix, Amazon, iTunes and Vudu all have 4K available. There are also Ultra HD Blu-ray players and gaming consoles, like the PS5 and Xbox Series X. If you have a PC, many video cards from the last few years can render games at 4K, with varying degrees of success. 

We’re starting to see the roll-out of ATSC 3.0, now known as NextGen TV. With a NextGen TV tuner, or a TV with one built in, you’ll theoretically be able to watch free 4K TV over the air. Just like the initial roll-out of HDTV at the turn of the century, it’s going to be a while before 4K programming is common over the air.

2K

Before “4K” became common, you’d almost never see “2K.” It was pretty much just a cinema resolution, which is why you’ll sometimes see 2K used to refer to a “master format.” Most digital cinema projectors used in theaters are 2K resolution (some are less). It’s 2,048 pixels wide, and again, no vertical resolution is specified by the DCI.

But now that “4K” has gained traction as a term used to describe TVs and content, “2K” is becoming increasingly common as shorthand for the 1080p resolution used by most smaller and older HDTVs, as well as Blu-ray. 

1080p or Full HD

Remember how we talked about digital cinema resolutions only specifying the horizontal resolution? Well TVs, on the other hand, have historically used the vertical to describe resolution (going back to the glass tube days). So 1080p is the vertical resolution. Nearly all HDTVs have an aspect ratio of 1.78:1 (16:9, aka “widescreen”), so that means a horizontal resolution of 1,920 pixels (1,920×1,080).

This is another source of confusion, since decades of TV discussions have talked about vertical resolutions, and then all of a sudden we’re talking about “4K TVs,” which refers to the horizontal resolution. Don’t blame me, it wasn’t my idea.

Which is why 1080p is not “1K.” If anything, as mentioned above, it’s “2K” by the same logic that UHD TVs are 4K. That said, most people don’t call 1080p 2K; they call it 1080p or Full HD.

By the way, 1080i is the same resolution as 1080p, but no modern TV is 1080i. However, most HDTV broadcasts, including those from CBS and NBC, are still 1080i. 

720p

Roughly half the number of pixels of 1080p. It’s rare to find a TV that’s 720p anymore. However, all ABC, Fox, ESPN, and their affiliated/sister channels broadcast at 720p. This goes back to the initial HD transition at the turn of the century. And if you’re wondering why your TV doesn’t say “720p” on those channels, check this out.

Monitor resolutions: WUXGA, WXGA, WXXXGA, WXCBGBSA, WXLADYGAGA 

In the computer world they use an incomprehensible and shockingly un-user-friendly jumble of letters to describe resolution. Well, not “shockingly” since these are computers.

Look, I’m a computer guy, building my own PCs since the early ’90s, and even I can’t tell you what half these letters mean. I can understand that initially they were implemented to make things easier, but we’ve got so many resolutions and combinations that now they’re just annoying.

Basically, the ones you’re most likely to see are FHD (1,920×1,080) and WUXGA (1,920×1,200). The rest, you can dive into and print yourself a cheat sheet from this.

Fortunately, the only time most of you will come across this letter goulash is if you’re looking for a cheap data projector or a computer monitor.

There are also computer monitors that have unique resolutions like 5K (5,120×2,880) or ultra-widescreen 21:9 aspect ratios with crazy resolutions like 3,440×1,440. There are so many variations we couldn’t hope to cover them all. 

samsung-cf791

Samsung’s CF791 ultrawidescreen monitor has 3,440×1,440 pixels, or UW-QHD (Ultra Wide Quad HD) resolution.


Sarah Tew/CNET

Bottom line

When you boil it all down, here’s the takeaway: Older and smaller TVs are HD, 1080p. Nearly all new TVs are 4K Ultra HD, which have four times as many pixels as 1080p. Someday you might have an 8K or even 10K TV, but that’s a l-o-o-o-o-ng way away.

Here’s where I remind you that more pixels doesn’t necessarily mean a better picture. There are other aspects of picture quality, such as contrast and color, that are far more important than resolution. 

In the future, resolution might become irrelevant. Technologies like MicroLED separate size and resolution, so your future 50-inch bedroom TV will have a radically different resolution than the 100-inch living room TV, as opposed to now where they’d both be 4K with different size pixels. Thanks to advancements in video processing, though, this won’t matter. They’ll all look sharp and detailed. 

First published in 2016. Regularly updated with new info.


As well as covering TVs and other display tech, Geoff does photo tours of cool museums and locations around the world, including nuclear submarines, massive aircraft carriers, medieval castles, airplane graveyards, and more.   

You can follow his exploits on Instagram and YouTube about his 10,000 mile road trip. He also has written a bestselling sci-fi novel about city-size submarines, along with a sequel.  

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