The world of home theaters involves plenty of key terms, some of which can be confusing. I regularly get asked what the differences are between aspect ratio and screen resolution, so I’ve written this article to explain everything in more detail.
In home theaters, aspect ratio refers to the screen’s width against its height and is expressed as a number (16:9) while screen resolution refers to the number of pixels that make up an image; higher numbers mean a more detailed picture.
Although that’s basically the difference between aspect ratio and screen resolution, it’s worth understanding both terms in more detail so you know exactly what to look for in your home theater devices. This is what I’ll discuss in this article.
Aspect ratio vs. screen resolution
Before I explain things in more detail, here is a handy chart that summarizes the main differences between aspect ratio and screen resolution:
| Aspect ratio | Screen resolution | |
| Definition | Aspect ratio refers to the width of the screen versus its height, and so effectively signals the shape of the picture (square, widescreen, etc.) | Screen resolution refers to the number of pixels that make up a screen’s image. Although commonly written as a single number, it should be written as 2 numbers |
| Information | Aspect ratio will generally signal whether an image is shown in widescreen or not, but can also refer to whether the image has been modified to fit a screen | Can also be named pixel or spatial resolution. Screens have native resolutions that images will need to be upgraded or downgraded for |
| Examples | 16:9, 4:3, 1:1 | 1920 x 1080, 3840 x 2160 |
Both aspect ratio and screen resolution are probably terms you’ve encountered before, as they’re often used by companies to sell their products. However, both terms are only relevant to an extent, particularly if you’re not completely aware of what they mean.
In home theaters, it’s not really a case of aspect ratio vs. screen resolution because you need both factors rather than one or the other. For example, aspect ratio refers to the shape of the screen on which you’re watching the media, while screen resolution refers to how sharp that image will be.
It’s fair to assume that any media bought in the last 5 years or so will be both widescreen and HD, which denotes aspect ratio and screen resolution. However, there are other versions of both factors, so I’ll look at these in more detail below.
Also read: Guide to screen sizes in home theater
Aspect ratio in home theaters
We should start with aspect ratio because it’s the slightly more confusing of the two, and also the one that most people brush over when choosing a TV or projector. After all, if the media is already presented in a particular resolution, then we don’t need to think about it, right?
Generally speaking, all widescreen HD media will be presented in 16:9 aspect ratio, but this might also be called 1.78:1. In short, this means that for every 1 unit in height, the screen is 1.78 units wide. It’s the most popular format for TVs, computer monitors, and projectors.
A slightly less common format is 2.35:1, but this is mainly reserved for projectors rather than TVs. It’s the format used in movie theaters and provides the highest level of immersion currently possible from a movie screen. If you’re stepping up your home theater game, you might want to look into this.
The only other aspect ratio worth mentioning here is 4:3, although you won’t buy a screen with this aspect ratio any more. It was used pre-HD, so any older media you have is likely presented in this aspect ratio.
When played on a widescreen device, the media simply sits square in the screen. We’re probably all too familiar with the large black rectangles down either side of the screen, and this is why. Also referred to as “video format”, it’s being phased out in favor of widescreen.
How to choose the right aspect ratio
Choosing the right aspect ratio for your home theater really isn’t that difficult. Effectively you only have 2 choices, but it’s most likely you’ll stick with 16:9. This is a common format for both projectors and TVs, and is the format used for the vast majority of media.
Another reason why it makes most sense to choose 16:9 is that it can play other formats (such as 2.35:1) with minimal masking. Going the other way and trying to play 16:9 on a 2.35:1 screen won’t be unwatchable, but it won’t be as nice.
Similarly, if you’re investing in a projector, then currently no projectors work at a native ratio of 2.35:1. Screens come in this format, but projectors have to be modified using new lenses. Therefore I’d recommend 16:9 as your go-to aspect ratio.
Check out my recommended projector screens.
Screen resolution in home theaters
Screen resolution is arguably the one we’re more familiar with because it’s regularly used to sell TVs and projectors. For example, HD, 4K, and 8K all refer to screen resolution, but what do they mean?
As I explained earlier, screen resolution refers to the amount of pixels that make up a digital screen. It’s usually expressed as a single number (such as 1080), but in fact involves the height and width of the screen.
The lowest HD resolution you’ll find is 1280 x 720, which is also called HD ready. However, we’ve all moved on from that, and the lowest you’ll probably find in your home theater is 1920 x 1080, which is also known as full HD.
Read my article in which I comprehensively compare 1280 x 720 and 1920 x 1080 resolutions.
4K is the most recent addition to screen resolutions, and measures at 3840 x 2160. But why is it called 4K? In short, the width is almost 4000 pixels, and by extension the screen resolution uses 4 times more pixels than full HD. 4K is also known as Ultra HD.
Of course there’s also 8K, which is 7680 x 4320, and provides 16 times the screen resolution of normal HD. However, there’s currently little to no media in this resolution, so I won’t talk about it much in this article.
As you probably already know, the higher the number of pixels in a screen, the sharper the image quality. However, that only holds true to a certain extent. This is because all HD screens with a 1080 resolution contain the same amount of pixels, regardless of the size.
What this means in terms of a home theater is that you need to aim for a higher resolution if you want a big screen. If you’re considering a screen bigger than 50 inches then I wouldn’t bother looking at anything less than 4K. In fact, you might find it difficult to find a lower resolution at this size.
What is native resolution?
Generally speaking, all TVs and projectors will be advertised with a native resolution. This simply refers to the resolution that makes the screen look its best, but can be changed to a lower resolution if necessary.
You might find this useful if you’re watching older media on a 4K screen, as it could have issue trying to produce a good quality image. However, this is generally down to personal preference, but changing screen resolution is really easy.
How to choose the right screen resolution
Choosing the right screen resolution for your home theater is really easy: base it on the size of the screen you’re buying. But also, buy the highest screen resolution your budget can afford.
As I mentioned, anything bigger than 50 inches needs 4K. If you’re buying a screen smaller than 40 inches (why would you?), then full HD should be fine. In the gray area between these 2 sizes, you can choose, but I’d recommend 4K as standard.
Another reason for this is because you’ll want to future proof your home theater equipment to justify the investment. Screen resolution is one of the hottest areas of technological development, as 8K is on the horizon and we’re only just getting used to 4K.
It won’t be long until 4K is the “standard” format for home media, although I doubt full HD will every truly die off. 4K TVs are fairly reasonably priced now, as are 4K projectors, so it’s fair to assume your budget will be able to stretch to even a lower-end model.
How does this all fit together?
When it comes to choosing the best screen for your home theater, you need to factor in both screen resolution and aspect ratio. That said, aspect ratio is arguably the one you should concentrate on less because you’ll realistically only have 2 options to choose from, and one make much more sense than the other.
Size is probably a more important factor to consider than aspect ratio because this will have a greater impact on image quality. A big screen needs to have a higher resolution so the image still looks sharp, but this doesn’t matter as much on a smaller screen.
However, you also need to consider things like contrast, color, and saturation, which are all more important for good image quality than screen resolution. Why? Because an HD screen with high contrast and deep colors will be better to watch than a 4K screen with washed-out blacks.
Also, screen resolution might not be as important in the future as it is now. For example, Samsung’s new MicroLED TV adjusts resolution based on size, and so the latest version is able to produce a tear-inducing HD image on a screen 24ft wide!
The bottom line is that screen resolution and aspect ratio are just 2 of many factors that decide what makes a good screen. Use something like screen resolution as a starting point, but then investigate the device in more detail to see if it’s worth spending on.
Is this the same for both TVs and projectors?
TVs are probably one of the easiest devices to buy for a home theater because we’ve probably all bought a TV at some point in our lives. Providing you can check its resolution, saturation, contrast, etc., then you can make a fairly educated decision about whether it’s right for you.
However, for many people projectors can be a completely different issue. Firstly you have to choose both a projector and a screen, which doubles the amount of decision-making you have to do. Luckily it’s not that much harder than picking a TV.
For buying the projector, you simply follow the same path as buying a TV. Look out for its aspect ratio though, as this will dictate the type of screen you buy. This is a more important factor here, simply because your equipment needs to match.
Projector screens are where it gets a bit more in-depth. Not only do you have different materials to choose from, but you can also decide between fixed-frame and retractable screens.
Arguably the most important factor though is the screen’s size. This is related to image resolution because you can sit closer to a 4K screen than you can a HD one. This is because, as we’ve established, there are more pixels and so the image is still clear at a shorter distance.
For a HD screen, you need to sit around 2x the diagonal of the screen away. So for an 8ft screen, you need to sit around 16ft away. For a 4K screen, however, it only needs to be 1x the diagonal. In short, this means you can fit a bigger screen in a smaller space. Check out this buying guide for more information.
Some final thoughts
Aspect ratio and screen resolution are likely terms we’re all familiar with, but understanding them in more detail will help you to pick the best screen for your home theater.
Screen resolution is definitely more important than aspect ratio, but the general rule is to buy the highest resolution you can for the space available. I wouldn’t recommend buying anything less than 4K at this point because it won’t be long until this is the standard screen resolution.
Jason is a home theater expert with over 10 years of experience in setting up home cinema rooms and systems. What started out as a hobby soon transformed him into an authority in the audio-visual field. He is passionate about providing readers with accurate and up-to-date information on the latest audiovisual technologies and their applications for home theaters. Read more about Jason.