When somebody is buying a new flat screen TV, there are two common questions.
What size TV do I need for my room - and what is the best TV viewing distance?
The fact is that these two things are related, and the answer you get for one question will affect the other.
One of the great things about modern TVs is they are available in screen sizes much larger than an old-style CRT TV.
As they are much thinner and lighter, they can easily be hung on a wall or stood on a piece of furniture.
However, because we are not so used to these big-screen TVs, it can be difficult to decide which size is best for the room. And, where we should position the screen.
Do we just buy the largest screen we can afford, or is it possible to get a screen that is just too darn big for the room?
So, are there any guidelines that we can use to decide on the best TV or projector screen size for our room?
Let's take a look.
The size of a flat screen TV is usually measured on a diagonal line from the top left corner down to the bottom right.
Or, bottom left to top right, if you prefer.
Hopefully, it's the same!
This distance is often quoted in inches. And different manufacturers will offer various sizes in their product range.
Sometimes you may see the size of a TV listed as the width or the height of the screen. But using the diagonal distance is the conventional way.
Currently, there are two main types of TV - an LED and an OLED TV. You might be surprised to know that these two different types are available in very different screen sizes.
You can expect to find LED TVs ranging from about 15 to 80-inches. And, in some cases, more.
However, at the time of writing, OLED TVs are only available in larger screen sizes. Usually around 50-inch to 85-inch.
So, one thing you need to understand is that the size of the screen you buy may be limited by the type of technology you want.
If you want to learn more about the differences between LED and OLED televisions, check out my buying guide to the best flat screen TVs.
However, once you have decided on the type of HDTV that you want, how do you choose the right screen size for your room?
And, what is the best distance to view your TV from?
The first thing to appreciate here is that this isn't an exact science.
Yes, there are some calculations that we can make to give a better idea. And I will look at some in a while.
But, ultimately, there are several factors which can affect your opinion of the right-sized TV for your room:
You can put two people in the same room, and both may have a different opinion of the right size screen and the best viewing distance.
However, it can help to get some solid numbers to give us a starting point, so let us consider how we might do this.
I am going to suggest three ways that you can try.
The numbers presented here are based on the excellent work by Carlton Bale. If you like working with spreadsheets, you might want to download his home theater spreadsheet calculator.
The information here can be used for TV and projector screens.
In terms of watching television, the field of view (FOV) is the viewing angle between a person and the visible area of a TV screen.
The closer you get to the screen; the field of view gets wider – and your viewing experience will be more immersive.
However, if you get too close, then the FOV will probably be too wide for most people.
Have you sat in the front row in an IMAX cinema? You pretty much need to turn your head to see the action at the ends of the screen.
In that case, I would say the field of view is too wide. You may like it!
The field of view is commonly used to define a reasonable viewing distance.
In their guidelines for a movie theater, THX suggests a minimum field of view of 26° - although their recommended field of view is 36° for the back row.
So, a 26° FOV is the furthest distance away from the screen that they recommend. But, ideally, the best distance would be a field of view of 36° or closer.
SMPTE (Society of Motion Picture and Television Engineers) also provides guidelines on the best viewing angles for watching a screen.
Their EG-18-1994 standard suggests a minimum FOV of 30°. So, slightly further away than the 36° recommendation from THX.
Therefore, according to these guidelines, you want to aim for a field of view of about 30-36°. Although you can go closer depending on your preference.
Neither of the guidelines advises how close you can get – just a maximum suggestion for how far away you should be.
Remember, the smaller angle is further away, and the bigger angle is nearer to the screen.
So, less than 26° will most likely be too far away for many people.
And greater than 36° will be more immersive but will get to a point where it is just too close.
Also, you should bear in mind these recommendations are for a real movie theater.
So, while you can use them for guidance in your home, many people will often need to make some compromises.
Another point to remember is that these recommendations don’t take into account the image resolution. We will look at this in more detail in a while.
The recommended distance based on the field of view will vary depending on the size of your screen.
Fortunately, we can easily calculate the recommended viewing distances with some math.
Here is a calculator for working out the recommended viewing distance for a 16:9 screen based on the field of view. Just enter your screen size to see the results.
A TV screen has a fixed native resolution. Ideally, the image that you see on that screen will have the same resolution.
Go here to understand more about image and native TV resolutions.
However, if we move away from the TV screen, there comes a point where we simply can’t see all the detail in the image.
This maximum distance will vary depending on the resolution of the image and the size of the screen.
So, the further away you get from the maximum distance, you will be able to see less detail.
And the closer you get, then you will see more of the imperfections in the image resolution.
Therefore, if you want to be able to see all the detail of your high-resolution screen, there is a recommended distance that you must sit from the screen.
So, this is another way of deciding the best viewing distance for your TV.
You should bear in mind that this distance can vary depending on the person looking at the screen. Visual acuity will vary between people.
It is even common to differ between men and women. So, the next time that you have an argument with your spouse about the position of the TV, now you know why!
The generally accepted figure is that a person with 20/20 vision can detect detail as small as 1 arc minute - or 1/60th of a degree.
Therefore, as the TV resolution increases - and the TV pixels get smaller - there is a limit as to how far away we can see this detail.
If you are good with formulas, you can find more detailed information on visual acuity calculations here.
Alternatively, here is a calculator that shows the recommended distance by resolution for a 16:9 screen - for someone with 20/20 vision:
The two previous solutions won't necessarily give you the same recommended viewing distance.
So, you will either need to choose one or the other - or find a compromise distance that gives you the best balance between the two.
As I said previously, there is no absolute right or wrong here. It will often come down to personal taste, your eyesight or how you use the screen in your room.
So, if you don't want to choose between one or the other - or think that getting it exactly right isn't practical or suitable for your room - then another alternative is just to use a general rule-of-thumb that will give you a range to aim for.
One popular rule-of-thumb is to simply use one foot of viewing distance for each 10-inches of diagonal screen size. This might sound more complicated than it is:
This gives a field of view of around 40° - which is slightly closer than the THX recommendation of 36°.
However, this a good distance for those who want to be close enough to get a good immersive experience, without being too close.
Of course, if you like being closer still, that's up to you.
Something like this can be used as the starting point for a recommended viewing distance range.
I used to suggest a ratio of 1.5 to 3-times the diagonal screen size. However, considering increased screen resolutions and bigger screen sizes, I would now suggest a ratio of 1.2 to 2.5 times the diagonal width.
The lower end of the scale will give you a field of view of around 40°.
The higher end will give you a bit further than the maximum allowable distance under the THX guidelines. So around 20° rather than the THX maximum of 26°.
This will allow for the fact that a home theater is more likely in a communal living area - rather than a dedicated theater space. So, a longer distance might be required.
It feels about right for me as a maximum. Although something that far will be better for general TV viewing.
Nearer is better if you can.
Anything in this range will work well. All you need to decide is if you prefer being closer - for a more immersive experience with more detail - or further away.
Of course, these are only general guidelines, so feel free to go closer or further away than this if it suits you and your room better.
There are two ways we might approach this range:
Here are some examples of how to work this out.
If you already know the screen size for your room, then you can use this to calculate a good viewing distance.
For example, if you have a 50-inch screen, then your ideal viewing distance will be:
Or 5 to 10 feet.
The following table shows a range of common screen sizes and shows a suggested minimum and maximum viewing distance.
I have rounded the numbers a little to make it easier to read:
You can use this as a guideline when deciding where to place your TV and furniture in the room.
Alternatively, you can look at this from the other direction.
Start with your viewing distance and then work out a good screen size.
In many rooms, the viewing distance from the screen is pretty limited. There aren't usually too many options where you can put the TV and your home theater seating.
Therefore, if you can estimate how far from the TV you will be sitting, then you can get a rough idea of the best screen size for that room.
This time you can divide your viewing distance by 2.5 to get the minimum screen size - and by 1.2 to get the maximum screen size.
So, for example, if you know the viewing distance in your room will be about 10 feet (or 120-inches), you can work out that a good TV size will be in the range of:
Now, that still gives us quite a bit of choice, but at least we can rule out screens below 48-inches and we have a better idea of where to start looking.
I’ve rounded the numbers a little in the chart below to make it clearer:
I think the most useful number in this method is the minimum screen size.
For example, if you are going to be sitting 14-feet from the screen, then you should be looking to buy a TV of around 68-inches and above. Ideally, you need a big screen from that distance.
Also, remember, these are only rough guidelines.
So, if you want to watch an 80-inch screen from 3-feet then go ahead.
There's no law against it!
Over the years I have seen a few people asking what the best viewing distance for a Sony TV is. You can insert any brand you like there - LG, Samsung - whatever.
The simple answer is that the brand of your TV doesn't matter. Regardless of who makes it, they all have the same important specifications - screen size and resolution.
These are the important features to consider.
So, in case you were wondering, the issue of viewing distance is the same for any brand of television.
These guidelines give us a good starting point.
However, as I said earlier, this isn't an exact science. Two different people will probably have two different opinions on what is a suitable screen size for a room.
So, now you have a rough idea of your screen size and viewing distance, here are a couple of extra points to help you make your final decision.
If you will mainly be watching high-definition or 4K Ultra HD images, then a larger screen will allow you to appreciate the extra detail more. And, it will also look great if you sit closer.
In this case, you will probably benefit more from:
On the other hand, if you are still watching a lot of standard-definition TV, then the reduced resolution may be more obvious on a larger screen.
Therefore, you may see the imperfections more if you sit too close.
Or a smaller TV may hide the reduced resolutions more effectively.
If you will mostly be watching movies, sports and documentaries. Or anything where you sit down for a long period and concentrate.
Then a larger screen is perfect for you to appreciate the action and detail.
You may also enjoy being closer to the screen.
On the other hand, if much of your TV viewing is for shorter programs that require less attention. Or, your TV is on 'in the background' much of the time.
Then a bigger screen may be too overwhelming in the room and so a longer viewing distance/smaller screen size may be better.
A large TV installed on a wall can sometimes integrate into a room more easily than one standing on a piece of furniture.
The size of the wall and the fact that the screen seems to be more 'removed' from the room can often make a larger TV to appear slightly smaller and less obvious.
However, standing on a unit or TV cabinet, the television can appear to be more 'on top of you' and a larger size may appear too big.
Be careful if you go into a shop to get a feel for the size of a particular TV.
A large shop floor with many other TVs around can make it difficult to judge the size of a screen. If possible, try and see a similar-sized screen in someone's home where you will get a better perspective on the size.
Another trick you can try is to cut a piece of wood or cardboard to the same size as the TV you are thinking of getting.
Place this in the approximate position in your room and you will get a good idea of how big the TV will look when you buy it.
In my experience, you will get used to a large screen very quickly.
When you first install a large flat screen TV it may seem ridiculously big compared to what you may have been used to.
However, you will very soon get used to the new size... and you may even start wishing you bought the next size up.
In my opinion, if in doubt... go for the bigger one!
If you are wondering about the best viewing distance for your room, it can seem a difficult choice.
However, once you think about things logically, then it can become much clearer.
Get a feel for a good viewing distance by working it out from your screen size. Then, consider the way you will be using the TV and the type of things you will be watching.
There are similar arguments for choosing the right TV screen size for your room.
You can get a rough idea by working out the viewing distance you will have. Then, you can calculate a broad range of suitable sizes.
After that, you need to consider things like the type of images you will be watching on the TV, how you will be using the screen and the location in the room you will be installing it.
Oh, and don't forget the golden rule... if in doubt, get the bigger one!
Paul started the Home Cinema Guide to help less-experienced users get the most out of today's audio-visual technology. He has worked as a sound, lighting and audio-visual engineer for around 20 years. At home, he has spent more time than is probably healthy installing, configuring, testing, de-rigging, fixing, tweaking, re-installing again (and sometimes using) various pieces of hi-fi and home cinema equipment.