Best Home Theater Room Sizes and Dimensions

It can be difficult deciding how much space you need for your home theater, so I decided to do some research into the best home theater room sizes depending on what kind of viewing technology you plan to use.

So, what’s the best home theater room size and dimensions? While there’s no perfect size for your home theater, bigger is better. For a fully immersive experience, 20ft long by 15ft wide is best, with high ceilings. However, smaller, typical family rooms around 10ft square are also fine for use with a large TV.

The biggest deciding factor in choosing the dimensions for your home theater room will be the size of your TV or projector screen. To help you make a more informed decision, I’ve looked into this in detail and have produced a handy table based on the most common screen sizes. Read on to find out more.

The Best Home Theater Room Sizes And Dimensions

As I mentioned above, one of the most important factors when choosing the size of your home theater room is the dimensions of your viewing screen. Each has a suggested viewing distance, which is the minimum distance between you and the screen that allows for the best picture. I’ll discuss how to work out this distance in more detail below, although there are plenty of calculators online too.

However, another important thing to consider is the acoustics of your space. Not only do you need to ensure that your speakers are powerful enough to produce enough sound to fill the room, but you also need to make sure that your room is the right shape to deal with the sound waves.

An improperly planned home theater room will cause sound waves to bounce across each other, resulting in muddy sound that’s difficult to distinguish. While many people probably won’t have the ability to reshape a room, this fact is worth bearing in mind if you’re starting from scratch and have a level of flexibility over the space you plan to use.

Ideally, the best home theater rooms won’t be square. While this isn’t a necessity, I’ve found that rectangular rooms (ones longer than they are wide) are best for viewing and acoustics. Channeling the sound along a rectangular room will result in better quality in your viewing area, whereas in a square room there’s more chance for the sound waves to bounce across each other.

The most important things to know when choosing the best size for your home theater are screen size and speaker system. For example, surround sound will require more planning than stereo sound, and regardless of what screen and sound system you’re using, careful planning is essential.

My home theater room is around 20ft long by 15ft wide and features a projector screen instead of a TV. If you’re using a TV (even a large one) you will be able to use a much smaller room, and will essentially only be dictated by the TV’s viewing distance. For a large TV, I’d recommend a room at least 9ft long, and between 6 and 9ft wide. This will give you the best space for viewing and for acoustics.

The Best Shapes For A Home Theater Room

Obviously, not everyone will have the option to completely reshape a room, but if you’re building your home theater in a space such as a basement or garage, you will have some flexibility on shape. If you start with a square or rectangular room, you can easily modify the shape using drywall or other construction materials. Shape will have a big impact on acoustics, so here are the best choices for a home theater.

1. The Golden Trapagon

This is by far the best shape for a home theater room because it removes the issue of parallel walls. This in turn reduces the effect of sound waves bouncing, and results in much clearer sound. It’s the room shape used by industry professionals in both cinema and audio.

A trapagon is basically a cuboid with one short side longer than the other. While this might sound a bit confusing, it’s really quite simple. For example, if the screen wall is 21ft wide by 13ft tall, then the room itself would need to be 26ft long. The viewing wall (where you’ll sit) would then need to be 16ft wide and 10ft high.

golden trapagon

The ratio you’re looking for when designing this shape is 1.272:1. This will make the trapagon shape that essentially funnels the sound in your direction, and reduces reverberation and echo. Sound is much harder to control than picture, so this will give you a way to manage it.

2. The Golden Cuboid

This is the next best shape for a home theater room, and is a more manageable choice if you aren’t able to change the shape of your room. It works on the principle of the Fibonacci sequence, and uses progressively increasing values.

The easiest example to use is a room measuring 10ft high, 16ft wide, and 26ft long. Placing the speakers appropriately within this space will cause sound to carry and not cross waves, resulting in a crisper quality.

Obviously this size of space might not be achievable for everyone, especially considering 26ft is quite a long room. However, using the Golden Ratio you can work out the correct dimensions for the space you already have. The Golden Ratio is 1.618, and you should always start with height as your smallest variable.

If, like me, you don’t consider math to be your strongest point, use this handy Golden Ratio room calculator to work out the perfect shape for your space. Once you’ve got workable dimensions, all you need to do is throw in some drywall and you’re set with an excellent audio space for your home theater.

3. The Normal Trapagon

This room shape works on the same basis as the Golden Trapagon but doesn’t use the Golden Ratio. Instead, there’s less difference between the front and rear walls, and it’s essentially a cuboid. However, the slight difference in wall width will still funnel the sound.

There isn’t necessarily a best ratio for this room shape. Although it sounds a bit vague, I recommend doing everything possible to ensure there’s around a foot’s difference between the front and rear walls, with your viewing area being narrower than the screen wall. This shouldn’t be too difficult with a bit of intelligent drywall placement.

The Best Viewing Distance For TVs

As I mentioned above, the biggest factor for many when deciding on the best size for their home theater room will be the recommended viewing distance of the TV or projector. This will realistically be the minimum space needed between you and the screen in order for you to get the best picture and not get headaches from viewing.

There are different recommendations for calculating viewing distance, but I work it out by taking the screen size and multiplying by between 1.5 and 2.5. This is general because there’s no correct answer, but I generally take the screen size and double it. For example, if I had a 40” TV, I’d want to sit around 80” (6.7ft) away from it.

Another option is to do it the other way round, and work out what’s the biggest screen you can fit in your space. To do this, you measure the distance (in feet) between your viewing area and the planned location of your screen and then times it by 7.7. So, for example, if the space between couch and wall is 11ft, then your TV can be a maximum of 85”.

I think it’s best to try the second formula if you’re still planning your space so that you know what size screen to buy. However, if you already own a TV, calculate its viewing distance and you’ll know what kind of space you need. Here is a handy table for some of the most common TV screen sizes.

TV SizeRecommended Viewing Distance
40”6.7ft
48”8ft
50”8.3ft
60”10ft
65”10.8ft
72”12ft
80”13.3ft

Some tips to consider when deciding on screen size and viewing distance:

  • These are the minimum recommendations, and you might find that sitting farther away is better. Start with these distances and play around a bit until you’re comfortable.
  • These measurements are for normal HD 1080p TVs. If you’re using a 4K TV, then you have a much easier time ahead of you.
  • Because 4K has more pixels, the recommended viewing distance is 1:1. So, if your TV is 40” you only need to sit 40” (3.3ft) away.
  • HD TVs have the same amount of pixels regardless of screen size. So for bigger TVs, farther away is better if you don’t want to see the pixels.
  • Don’t forget to make sure your speakers are powerful enough to fill the space, and factor this in when buying them. Larger spaces will need either more powerful speakers, or simply more of them.

Best Viewing Distance For Projectors

Projector screens essentially follow the same calculation ratio as TVs, but you also have to factor in something called your eye’s subtended viewing angle. This is basically the maximum angle at which your eyes can take in information without having to move.

Math aside, the two main recommendations are 30 and 36 degrees. To save yourself some tricky formulas, use this simple calculator. An example to give you a feel for distance is that for a 120” screen, you should sit between 13.4 and 16.3ft from it. This will mean you’re able to see the whole picture without having to move your head or exhaust your eyes.

The explanation in the video will give a better insight and another method of determining viewing distance.

It almost goes without saying that projectors will need more space and should only be reserved for the most luxurious home theaters. 120” is a reasonably common screen size, and if you start going much smaller then you might as well stick to a TV. However, you won’t have as many issues with pixels using a projector, and a 4K projector will give you the cripest image possible.

Projectors come in different aspect ratios, and each one has a recommended viewing distance. Here are some examples of the most common viewing distances at different aspect ratios.

16:10 Aspect Ratio

Screen SizeViewing Distance Range
80”97-106”
100”122-133”
120”147-160”
150”184-200”

4:3 Aspect Ratio

Screen SizeViewing Distance Range
80”110-121”
100”138-151”
120”166-181”
150”208-227”

16:9 Aspect Ratio

Screen SizeViewing Distance Range
80”100-109”
100”125-137”
120”151-165”
150”189-206”

How Much Space Do You Need For A Home Theater?

I’ve done plenty of research into the best size for a home theater, and have come to a conclusion about how much space you need for one. The short answer is as much as possible. The bigger your home theater room, the more space you have for all the technology, and the bigger screen you can have.

The two biggest deciding factors when choosing your space will be:

  • Screen size and
  • Seating arrangements

As you have seen above, there are minimum viewing distances for screens, and so these should be considered the minimum length of the room you use as a home theater.

Once you’ve got the recommended length established, you should then use this to calculate the width of the space. Remember, rectangular is better when choosing your space, but in a pinch a square room will be fine providing you can add some acoustic treatments to stop sound bouncing across itself.

The final thing to consider is the size and amount of seating you need in the room. If you’re only catering for yourself and one or two other people then you can get away with a smaller room. However, if you plan on having plenty of friends round to watch the latest releases, then you’ll be better with a cinema-style seating arrangement. This will obviously take up more room and will probably require a bigger screen.

Read my article on various home theater seating plans

As you’ve probably gathered by now, acoustics are another important factor in deciding space for your home theater room. If you’re buying speakers, then you’ll need ones powerful enough to fill the space, but if you’ve already got a set then you might need to add more (such as ceiling speakers) to provide enough coverage for the room.

Square rooms are arguably the worst for acoustics, but careful speaker placement makes a massive difference. Combine this with some acoustic treatments, such as bass traps, and you’ll still have a usable space. Use this setup guide to establish Golden Rectangles for your speakers. This will minimize reverberation and improve sound clarity.

Also read my guide on deciding number of acoustic panels required for a home theater room.

What Is Considered A Large Room For A Home Theater?

large home theater size

Although the words “large” and “small” are very subjective, they’re thrown around a lot when discussing the best size for a home theater room. There are several factors I would consider when deciding if a home theater room is large, including:

  1. The space is at least 15ft long and/or at least 10ft wide.
  2. It would be more suited to a projector and screen than a TV, meaning a screen size of at least 80”, but more like a minimum of 100”.
  3. The room has a volume of at least 2,000 cubic feet.
  4. It’s similar in design and use to something like a garage or open-plan basement.
  5. It has ceilings around 8ft high, if not more.

A large home theater room will generally be one that you’ve either had custom built for the purpose, or converted from a space such as those listed above. Generally speaking, unless you live in a mansion, standard household rooms wouldn’t be considered a large home theater.

This is the kind of space where you can really go to town on your home theater planning, and would probably be any home theater enthusiasts dream. It’s the sort of thing you’d expect to see in a celebrity’s house on MTV Cribs. For most, this will probably be outside their capabilities, but if not, then enjoy yourself.

For a large home theater room, you’ll want to invest in the most suitable technology. A projector and screen will be a must to fill the space, and you’ll also need some powerful speakers, and plenty of them. It probably goes without saying, but surround sound will be much better for a large space. You’ll probably also want to supplement this with ceiling speakers and several powerful subwoofers.

How Small Can A Home Theater Be?

On the reverse of the point above, there’s no one answer for how small a home theater can be. My definition of a small home theater would be a normal household space, realistically between 9 and 12ft in size with a volume of 1,000 cubic feet or less.

However, a small home theater can be as small as you want it to be. There are some advantages to a small home theater, such as not needing as powerful speakers, but there are obviously also some drawbacks to the space too.

Smaller home theaters mean you’ll be limited with screen size. Sure, you can still buy a big TV, but just make sure you’re not sitting too close that you ruin the image. Similarly, you’ll be more limited in the amount of seating you can include, but as long as you have at least one chair it won’t matter, right?

Converting a small space into a home theater simply requires more careful planning. Consider these tips if you’re working with a smaller space:

  1. Start with a plan of your space. Measure dimensions, including height. This will give you a good place to start when choosing your tech.
  2. Plan where your seating will go. This should be your starting point because it’ll realistically be the biggest thing in the room.
  3. Using this, consider your options for TV placement. Mounting it on the wall will be a better idea because this uses up less floor space, giving you more room for activities.
  4. Plan your speaker placement next. Make sure they’re angled correctly so they point at your seating area, but won’t cross over on the way. This will result in muddy sound, something you need to avoid in a small space.
  5. Again, speakers can benefit from being mounted on the wall. Providing your subwoofer is on the floor, there’s plenty you can do with the satellite speakers.
  6. Once you’ve got a good plan, put it into practice. You might find that once you start putting speakers in that you need to alter things slightly, but at least having an initial plan gives you a better idea of what to do.
  7. Because it’s likely that you’re using an existing space, pay attention to things like ambient light and sound. Blackout curtains are a must, and you might want to think about including some acoustic treatments to improve sound quality.

There’s absolutely no reason why a small home theater should be any worse than a large one, providing you plan everything carefully and intelligently. At the end of the day, a large home theater is really a lot of empty space, and providing you’ve got seating and a good screen, what more do you need?

The Best Acoustic Treatments For Home Theater Rooms

The chances of you having a space that follows the Golden Ratio are quite slim, so acoustic treatments are an important addition to any home theater. This is particularly true in large home theater rooms, as the sound has further to travel and so has more chance of reflecting.

If you’re looking for good quality audio in your home theater, reflection is the last thing you need. Sound waves crossing over each other causes them to sound muddy, which is the last thing you want when you’ve spent all that money on a decent system.

To combat this, you want to use some acoustic treatments. There are plenty available, as they’re generally used in recording studios. You’ve inevitably seen that weird foam paneling on the wall in recording studios; it often looks like egg boxes or something similar.

Most people think that’s to soundproof the room, but it’s not. It’s actually to absorb acoustic reflections, thereby improving the final sound quality that reaches the microphone. Luckily, we’re looking for the same thing in a home theater, and so it’s a useful addition. Along with acoustic panels, you might want to add the following:

1. Bass Traps

These are pretty self-explanatory, and would probably be a better place to start than acoustic panels. Bass frequencies are a prime culprit for reflection, and so stopping this is pretty important.

Bass traps are essentially a specialized type of acoustic panel that’s designed to absorb bass frequencies. However, some good quality ones will also absorb mid-range and high frequencies too. That’s why I’d probably start with them, as you might find they’ll do the job.

Read this guide by Soundproof Central on bass traps which I think is definitive.

2. Diffusers

These are a great addition alongside acoustic panels, particularly in larger spaces. Without getting too bogged down in science, diffusers basically scatter reflected sound waves, rather than absorbing them. This stops a room from sounding very dull, which those full of acoustic panels can.

When sound waves reflect, they usually end up amplifying some frequencies and reducing others. This results in unbalanced sound, which is want we want to avoid in a home theater. Diffusers stop this by keeping the reflecting waves but changing their path.

Diffusers are probably the last thing you’ll want to add to your home theater, but can be a good addition to cancel out the effects of too much absorption. I’d recommend starting with bass traps, testing things, and then adding diffusers if you want more rounded acoustics.

There’s not really a right answer for how much acoustic treatment you put into a room. You could go mad and cover every wall, but then you’ll probably find all sounds in the room are flat and dull. While this might be great for some situations, it might not be best if you want an immersive sound experience.

If you notice some sound reflection in your home theater, I’d recommend starting with a few bass traps in what you consider to be the problematic areas. Start small, test it out, and then add more if necessary. Keep going until you’ve reached what you consider to be a good balance, and then ask for a second opinion. Everyone hears sound differently, so it can be useful to have your decisions checked.

Conclusion

So, although there’s not really a correct answer for the best size for a home theater room, there are plenty of factors to consider when planning your space. Starting with your screen size and recommended viewing distance will give you a good idea of the best size for your needs.

Also, if you’ve got flexibility over your space, favor shape over size. Acoustics are crucial in a home theater, so do everything possible to make sounds sharp and clear. Providing you get this correct, everything else should fall into place and you’ll likely realize that size isn’t everything.

Sharing is caring!