When it comes to buying a new TV or monitor for an inexperienced consumer, there are enough terms and acronyms to make you dizzy. There are 720p, HD, 1080p, FHD, 2160p, UHD, 4K and more – it can be overwhelming.
Without fully understanding the characteristics of the display in question, you run the risk of overpaying for what is ineffective. By today’s standards, using a 32-inch 720p TV as a computer monitor is on the verge of masochism.
Those of you who are not comfortable with having to sit 30 meters away from your TV for text to look crisp have probably heard of 4K. Today 4K screen resolution is considered the standard when it comes to high quality streaming and gaming. The fact is that many people don’t quite understand what 4K stands for or how it differs from terms like UHD and 2160p.
In this article, let’s talk about the differences between 4K, UHD, and 2160p.
What is 4K?
An easy way to remember the characteristics of a true 4K display is to make comparisons based on the number (4000) in that term. By definition, 4K displays have a resolution of at least 4000 pixels horizontally. This usually refers to a display resolution of 4096×2160, which is 8 million active pixels. This resolution has four times the pixels of a 1080p display.
However, the most commercially available 4K display resolution is 3840 × 2160. The first number, 3840, is the horizontal display resolution in pixels, and the second number, 2160, is its vertical resolution. This seems to violate the only 4K rule, but this is how the term was adapted.
The term “4K” originally comes from digital cinema resolution now called DCI 4K. The display resolution of 3840 × 2160 is now the 4K standard due to its widespread adoption among TVs and monitors. In most cases, a 4096×2160 screen resolution either stretches and distorts the image, or requires black boxes at the top and bottom – neither of which consumers will be happy to see.
So, to satisfy home consumers, 4K almost always means a screen resolution of 3840 × 2160.
What is UHD?
UHD stands for Ultra High Definition. Unlike 4K, where 4096×2160 is a true definition resolution, a UHD display is definitely 3840×2160.
However, despite how unusual true 4K is, UHD and 4K are interchangeable. However, from a technical point of view, the 3840×2160 display is only UHD.
Some retailers, instead of just using the two terms interchangeably, refer to 3840×2160 as 4K UHD, which is UHDTV1. 8K UHD is 7680 × 4320 called UHDTV2.
Going back to what we originally talked about the consumer-friendly definition of 4K, UHD TV 1 (now simply called UHD) and 4K are one and the same.
What is 2160p?
The term “2160p” is used to describe display resolutions where the vertical resolution is 2160 pixels. “P” stands for Progressive Scan, sometimes referred to as “Non-Interlaced”.
Progressive scan is a format in which the lines of each frame of a moving image are drawn sequentially. This is in contrast to interlaced video, where odd and even lines are drawn alternately for each frame.
Simply put, 2160p is vertical, which is 4K horizontal. At the same time, almost all 2160p display resolutions are also 4K (by its free definition).
Wait, are they all the same?
To summarize and compare, we can say that the display can be both true 4K and 2160p (4096×2160). However, a UHDTV1 display (currently simply referred to as UHD) always has a 2160p resolution as that refers to a 3840×2160 display resolution.
When UHDTV2 (or consumer-friendly 8K) becomes popular, UHD will no longer be synonymous with 2160p because UHD is tuned to describe both 4K and 8K screen resolutions. This is when it becomes more important to distinguish between 4K UHD and 8K UHD.
Finally, due to the adapted definition of 4K, the 3840×2160 resolution can currently be considered all 4K, UHD and 2160p. So, in normal cases, and based on the weakened definition of 4K, they are all the same.
When the term “4K” was coined, it caused a lot of confusion in the display market. Consumers were familiar with 720p being referred to as HD (high definition) and 1080p as FHD (full high definition). Using 2160p and UHD instead of 4K, it becomes consistent and easier to read.
However, retailers have started to cut this display resolution as 4K. This could be because “2160p” just doesn’t roll off the tongue very well, but it broke the format that many consumers are used to. Even worse, “4K” is not technically accurate when it comes to 3840×2160 – an honest argument against the popularity of the term.
Another reason retailers may be keen to label everything as 4K is because putting all these confusing names together makes a product more functional. A 4K UHD 2160p TV sounds like more than a 2160p TV, right? Well, that’s pretty redundant.
When you buy a new display with the latest high definition standard, know that 3840×2160 is what you need. However, there are other abbreviations and specifications that are not trivial – for example, check out the Online Tech Tips article on 4K versus HDR and Dolby Vision.