From 4K to UHD to 1080p: What you should know about TV resolutions
So many letters and numbers. What does it all mean? And what on earth is 8K?
Geoffrey Morrison is a writer/photographer about tech and travel for CNET, The New York Times, and other web and print publications. He's also the Editor-at-Large for The Wirecutter. He has written for Sound&Vision magazine, Home Theater magazine, and was the Editor-in-Chief of Home Entertainment magazine. He is NIST and ISF trained, and has a degree in Television/Radio from Ithaca College. His bestselling novel, Undersea, and its sequel, Undersea Atrophia, are available in paperback and digitally on Amazon. He spends most of the year as a digital nomad, living and working while traveling around the world. You can follow his travels at BaldNomad.com and on his YouTube channel.
4K, 8K, 1080p, HD and UHD. If you're shopping for a new TV, you've likely noticed these letter-number combos listed beside the word "resolution." But what's the difference between these resolution types? Is it worth paying more for an 8K TV versus a 4K TV? Does resolution even matter that much? Resolution may not be the most important factor when buying a new TV, but it's still something you should consider. Although it can get confusing, knowing what all the numbers really mean can help you feel more confident in your choice of TV.
Here's what you need to know about resolution when it comes to TVs. The short version:
4K almost always means the TV has 3,840x2,160 pixels.
UHD stands for "Ultra High Definition," also known as UltraHD, but basically means 4K.
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 TV 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.
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
Horizontal x vertical pixels
10,240x5,760 or 4,320
No consumer products
4K, Ultra HD, Ultra-High Definition
TVs, monitors, projectors
Some cinema projectors
Widescreen Ultra Extended Graphics Array
Full HD, FHD, HD, High Definition
TVs, monitors, projectors
HD, High Definition
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,
and others, is 3,840x2,160 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 3,840x2,160. Most companies just say both: Ultra HD 4K.
8K follows the same logic. If you're talking about TVs, it's twice the horizontal and vertical resolution of 4K TVs: 7,680x4,320. 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
, 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.
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 (1,920x1,080).
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.
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.
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 (1,920x1,080) and WUXGA (1,920x1,200). 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 (5,120x2,880) or ultra-widescreen 21:9 aspect ratios with crazy resolutions like 3,440x1,440. There are so many variations we couldn't hope to cover them all.
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.