Home Theater Calculator: Viewing Distance, Screen Size

Over the past several years, I’ve slowly constructed a spreadsheet to meet all of my home theater design needs. I noticed on various forums that others could probably benefit from this spreadsheet, so I cleaned it up and I’m now making it available to the public. Please download it and put it to good use!

The spreadsheet contains calculations for the following:

  • recommended viewing distances for a given screen size – for both flat panels and projectors (based on THX and SMPTE standards)
  • recommended viewing distances for a given display resolution – 480p, 720p, 1080p/1080i, 1440p, etc (based on Visual Acuity standards)
  • various screen aspect ratios (4:3, 16:9, 1.85:1, 2.35:1, custom ratios, etc.)
  • projector screen size & screen brightness with guidelines for recommended values (based on projector brightness and screen gain)
  • projector screen size & projector mounting location (based on min/max projector throw distances)
  • seat locations, a second row stadium seating platform height calculation, and a few other goodies.

Microsoft Excel Icon theater_calculator_v4.1.xlsx

Please report any problems or suggestions via e-mail or the comments form below.

Revision history:

  • Version 4.1: Added details on how to enter 4k and 8k UHD resolutions.
  • Version 4.0: Added Anamorphic (horizontal expansion) front projector lens option, which adjusts projector brightness and throw ratios when selected.
  • Version 3.7: Clarified back row platform height input fields, modified formulas to prevent negative platform heights (user info message instead), changed spreadsheet defaults to better fit a typical home theater.
  • Version 3.6: Added feature to allow calculation of Visual Acuity Viewing Distance based on eyesight of the viewer. The default is 20/20 vision; changing the input to 20/10 vision with show that the viewer will be able to spot resolution deficiencies at much greater distances due to more acute eyesight.
  • Version 3.5: Fixed bug in the aspect ratio input that caused international users to have problems (problem was related to using “,” as decimal delimiter instead of “.”) Added cells to the far right of the spreadsheet to allow changing and adding custom screen aspect ratios.
  • Version 3.4: Widened columns that were causing being truncated for international users.
  • Version 3.3: Added 2.35:1 aspect ratio back.
  • Version 3.2: Changed anamorphic aspect ratio from 2.35:1 to 2.370370:1, which is the correct value for a 16:9 projector with a 4:3 anamorphic lens. Corrected spelling mistakes on one of the extra tabs within the spreadsheet.
  • Version 3.1: Fixed unit conversion formula that was causing “Second Row Field-of-View Width” to not calculate when any unit besides “inches” was selected.
  • Version 3.0: Added minimum viewing distance calculation, added conditional feedback on seating distance for each specification (seating distance too far, etc.), added first row and second row seating distances (for conditional feedback on seating distances), added field-of-view results (in degrees), added ability to calculate projector throw distances for any screen size (just enter the throw information for one screen and it will interpolate for other screen sizes), fixed mis-spelling that was causing formulas to break.
  • Version 2.9: Added 2.40:1, 2.70:1 screen aspect ratios, added ‘hover’ comments to better explain the different seating distances; added conditional formatting on the screen brightness result cell (red if brightness is too low, yellow if it is close to being too low).
  • Version 2.8: Added charts for “seating distance vs. screen size based on screen resolution” and “seating distance vs. screen size based on published standards.”
  • Version 2.7: Edited notes fields to improve clarity for data entry fields.
  • Version 2.6: Added LCD/Plasma support. Added 16:10 aspect ratios for LCD monitors. Added hints to help enter panel resolutions (hint lists commons resolutions). Added pixel density calculation (useful when using as a PC monitor). Added dot pitch (in mm – millimeters). Added total pixel count. Fixed spelling errors.
  • Version 2.5: Updated screen brightness calculation to adapt to entering screen width vs. height vs. diagonal measurement. Thanks Brad for finding the problem.
  • Version 2.4 – 01-Nov-2004: First Public Release. Uses both metric and English units. Converts between many units. Gives hints for some common input values such as aspect ratio. Seating distance. Platform height. Viewing angle. Screen brightness. Many other features.

 

If the spreadsheet is too complicated for you…

If you don’t like working with spreadsheets, enter your screen size below to see how close you’ll need to sit to fully appreciate various screen resolutions.

Enter screen size: inches diagonal

  • For 480p (720×480) resolution, you must sit:
    feet or closer to see all available detail
  • For 720p (1280×720) resolution, you must sit:
    feet or closer to see all available detail
  • For 1080p (1920×1080) resolution, you must sit: (recommended minimum distance)
    feet or closer to see all available detail
  • For 4k (3840×2160) resolution, you must sit:
    feet or closer to see all available detail
  • For 8k (7680×4320) resolution, you must sit:
    feet or closer to see all available detail

Note about “or closer” viewing distances calculated above: if you sit closer than the distances shown above, you will be able to see some (but not all) of the detail offered by the next higher resolution.

484 Comments

  1. I have a media room size of 20ft * 14ft but my projector can be placed at 12ft since there is a beam in the middle. I need 135 inch screen size .Can you tell me which project i could purchase for less than 1300$

  2. At what height home theater screen should be fixed from floor.?

  3. Why do American’s insist on Inch’s when sizing – it’s so illogical and hard to calculate with.

    1. Author

      It’s because that’s the way TVs are sold in the US, and the US is a big enough market that there is no way to force conformity to external standards. As you may have noticed, the inputs and outputs on the spreadsheet have configurable units…including metric.

  4. Firstly, thanks for tackling a complicated subject in such a thorough manner! Great presentation, too. My question: I just bought an LG 55″ OLED 4K 3D TV (LG OLED55E6P). Would I still use the “3 ft or closer for 4K” as recommended by the chart, i.e., would the OLED and/or 3D make any difference? (And while 3 ft would be awesome in the theater room on your website, I’m having a hard time imagining it in a living room which is considerably larger and oddly-shaped. Any thoughts or should I confer with an interior designer on that one?…lol). Thank you!

    1. Author

      I think you’re ask the wrong question. You’ll have huge benefits from OLED in terms of black level, contrast ratio, color accuracy, and all other aspects of picture quality. It’s awesome hardware. For the resolution aspect specifically, you may not be able to perceive ever possible detail of a 4k image, but that’s not what’s most important for picture quality. There’s nothing wrong with the setup you have. Unless you want to spend more and have space for a bigger screen, you’re setup is probably ideal for your situation.

      1. Taking this a step futher, I have the same TV as above. Is there a gradient for resolving 4K detail between 3’ and 7’. Or it it a binary choice. Let’s say you sit 5’ away with a 55” inch screen. Would it be reasonable to say that you can resolve some, but not all of the detail or does it all come into focus at 3’ and anything less is 1080p. You have heard the saying, half a loaf is better than none”. How does that apply to your calculator? Although your calculator is widely used and respected, there have a been a few comparisons where a group of viewers, doing an A/B comparison claimed to see a difference between 1080p and 4k, even at 7 or 8 feet. Ie, they all picked the 4K screen as the one w/more detail.

        Off topic here, but the marketing of the 4K Apple TV as 4KHDR is now conflating two different concepts and implying that 4K is delivering more value than it actually is – 4K is now the Trojan Horse containing the HDR payload.

        1. I think a better way to think about it is if you are sitting beyond the maximum for resolving 4k detail, then you may as well have had 1080p (you are paying for 4k but getting no benefit).

        2. Author

          Yes, there is a gradient for resolving resolution detail and you can get some of the benefit at “almost 1080p” distances. In fact, you can get all of the benefit in some situations, such as geometric and high-contrast test scenes. The spreadsheet assumes a “worst case” of wanting full resolution benefit on scenes that are not high contrast. The graph in this post explains it pretty well: https://carltonbale.com/does-4k-resolution-matter/

          You’re absolutely correct on “4kHDR”. The picture looks incredible, but in most cases the gain is because of the “better pixels” from HDR rather than the “more pixels” from 4k.

  5. excel download is not working for older excel versions. make it compatible please.

  6. So I am building walls in my 19′ long by 17′ wide movie theater room. Ive read lots of blogs about setups, but I cant find anything on what the best system is for my room. Should I go 5.1.2, 7.1.2 or 7.1.4 in a 3 rows of seating theater? the Atmos speakers will be mounted in ceiling. Also what is a great speaker set, receiver and projector all within about $5-$7,000 total? thanks love your page

  7. Hi Carlton, First thank you very much for helping us.

    I have a room 23′ X 19′ , I am planing to put 150 inch screen on 23′ wall and viewing distance is 19 feet and adding 2 rows.

    is that enough distance to watch 150 inch screen from 13 to 19 feet distance? is something I am doing wrong.

    can you please suggest right projectors?

    Thanks in advance.

  8. Do not believe the Jobs/Apple hype for the Retina displays which gives you the 60 pixels per degree you’re using here.

    You should change your calculator to the more industry accepted limit of human vision of between 0.3 to 0.4 ArcMin per pixel or 150 to 200 pixels per degree.

    This would make a huge difference on what people could perceive where a 1080p 50″ display could now be noticeable out to 20 feet rather than the 7 feet you’re stating now.

    1. This comment intrigued me, so I did some research, and it is true. Jobs’ claim was based on 20/20 vision, which is a long way from being the best humans can do. Raymond Soneira, a go-to guy for displays, suggested 0.6 arcmin, but most analyses hover between 0.3 and 0.4. Take a look at Clarkvision’s page on eye resolution, or the cultofmac’s article on why retina isn’t enough.

  9. Great tool 🙂
    Could you add recommended ft.lamberts for HDR?

  10. Ok looking at a 60inch 4K TV… The ideal viewing distance is… 46,8 inches??? This can’t be true… You buy a 60 inch to sit comfortably AWAY from your TV not so you have to sit almost NEXT to it!

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