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.
theater_calculator_v3.7.xlsPlease report any problems or suggestions via e-mail or the comments form below.
Revision history:
- Version 3.7 - 14-June-2008: 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 - 21-July-2007: 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 - 20-July-2007: 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 - 27-June-2007: Widened columns that were causing being truncated for international users.
- Version 3.3 - 16-Feb-2007: Added 2.35:1 aspect ratio back.
- Version 3.2 - 13-Feb-2007: 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 - 15-Dec-2006: 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 - 13-Dec-2006: 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 - 01-Dec-2006: 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 - 20-Nov-2006: 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 - 29-Sept-2006: Edited notes fields to improve clarity for data entry fields.
- Version 2.6 - 09-May-2006: 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 - 27-Nov-2004: 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.
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November 15th, 2006 at 8:13 pm
[...] Based on the resolving ability of the human eye (with 20/20 vision it is possible to resolve 1/60th of a degree of an arc), it is possible to estimate when the differences between resolutions will become apparent. Using the Home Theater Calculator spreadsheet as a base, I created a chart showing, for any given screen size, how close you need to sit to be able to detect some or all of the benefits of a higher resolution screen. (Click the picture below for a larger version.) What is chart shows is that, for a 50-inch screen, the benefits of 720p vs. 480p start to become apparent at viewing distances closer than 14.6 feet and become fully apparent at 9.8 feet. For the same screen size, the benefits of 1080p vs. 720p start to become apparent when closer than 9.8 feet and become full apparent at 6.5 feet. In my opinion, 6.5 feet is closer than most people will sit to their 50" plasma TV (even through the THX recommended viewing distance for a 50" screen is 5.6 ft). So, most consumers will not be able to see the full benefit of their 1080p TV. [...]
December 12th, 2006 at 1:22 pm
Great tool. It looks though that you have diagonal misspelled though in the dropdown menu in cell e7 (diagional). It makes it useless as the rest of your cells look to key off the proper spelling.
December 12th, 2006 at 1:43 pm
Thanks Frank. I noticed the same problem over the weekend. I've posted a new version (3.0) with this problem corrected as well as many other feature additions.
December 14th, 2006 at 11:23 am
Terrific tool. I see only one cell with strange results. It is the "Field of View Width (second row center)." Is this the width of vision at that distance from an object, or is this supposed to be the subtended viewing angle as in the cell above it for the first row?
December 15th, 2006 at 8:22 am
Randy: Thanks for the feedback; the second row field-of-view width calculation was supposed to be the same as the first row. The unit conversion for “Field of View Width (second row center)" was not calculating properly. Version 3.1 fixes that problem.
December 25th, 2006 at 9:52 am
Hello!
I got through your website when I searched on Hometheater calculator. So far your calculator has the most info to it; But I am still getting confused about certain specs/info. Are there any similar calculator out there, that would give the option of what screen size(diag,W,L)if you want to use front projection or Rear or Direct view Dispaly, seating distance, if you want to add additional rows? All would have to be based on actual room dimensions. It has been so confusing on the ‘rule of thumb’ for screens size (i.e 3 to 5 times of the seating distance). Are they talking about diagonal or Width and Length? how would you decide of the actual height of platform if you’d like to add a 2nd row etc…Basically all the info/detail that you have on you calculator but by just inputting the actual dimenssions of the room?
thanks for your help!
Sidney
December 30th, 2006 at 11:08 am
Sidney, I haven't seen a calculator that starts with a room dimension and gives you possible layouts, but I think that is a great idea. I'd see if I can add that capability at some point to my spreadsheet. My spreadsheet can currently answer your questions, but you'll have to enter different screen sizes and then see what the "maximum recommended seating distance" is for each screen size. The smallest screen size that gives a viewing distance equivalent to your back row distance from the screen is the screen size you should choose. (In other words, don't use the rule-of-thumb you mentioned, use the THX / SMPTE recommended values in the spreadsheet.)
There is really no way to recommend the type of display based on room layout. The general guideline is to get a front projector if you have complete light control (zero visible sunlight) and want a giant screen (larger than 60 inches). If you don't have complete light control, get a flat panel or rear projection unit that fits your budget and aesthetic requirements.
The second (or third) row seating height is dependent on two factors: the height of the screen and the height of the the head of the someone sitting in the front row. Basically, you don't want to have the screen blocked by someone's head when you're in the second row. My calculator will currently perform that calculation; just enter the info for screen height and first row head height in the appropriate cells.
As for number or rows, Allow enough room for a reclined chair (66 inches) and a walkway in between rows (12 inches minimum; 18-24 inches recommended). Then look at the spreadsheet for min/max seating distances. For a room 21' deep, 3 rows would put the front row too close to the screen. I'd stick with two rows.
January 2nd, 2007 at 9:00 pm
I am trying to determine the proper height for mounting a tv on a wall. Is there a formula that will calculate this by knowing the viewing distance, nominal height of eye level and using recommended viewing angle of 20 degrees.
January 6th, 2007 at 9:25 am
Lawrence: The formula would be (ArcTAN of 20 degrees)*(distance to screen) + height of viewers head from = height of screen from floor. (If you enter this into Microsoft Excel, you'll first have to convert degrees to radians for the ATAN (ArcTan) function to work. I'm assuming you're measuring to the middle of the TV screen, not the bottom.
As a simple rule of thumb, I'd suggest picking a point 1/3 (or up to 1/2) of the way up from the bottom of the screen and mounting that at eye level. Mount it higher only if you are worried about blocking viewers behind you.
February 5th, 2007 at 8:49 am
Dear Carlton,
This is brilliant. your calculator is of immense value, especially for computer unsavvy people like me.
for this very reason i would appreciate if you could send me te exact typed code for the screen height that you mention above as i am quite sure that i cannot define this myself.
best reagrds
aditya
February 6th, 2007 at 8:12 am
Aditya: To tell you the truth, I'm not sure what the "recommended viewing angle of 20 degrees" means in terms of screen height. I have a hard time recommending it or including it in my spreadsheet because I don't even know if it is above or below horizontal, plus I'm not sure it's valid either way.
For screen height from the floor, the nominal eyeball height from the floor is 40 inches. The bottom of the screen should be no more than 40 inches from the floor. Ideally, the center of the screen would be 40 inches off the floor if you have one row only.
If you have two rows, my spreadsheet has the calculations (near the bottom) to determine screen height based on the first and second row seat heights and distances from the screen. This is to prevent the first row from blocking the second row.
February 11th, 2007 at 5:45 am
Hi,
You may want to add 2.37:1 to the drop down list of allowed AR's in your excellent spreadsheet as all the anamorphic horizontal expansion lenses are 1.33. 1.33 X 1.78 gives 2.37:1, not 2.35:1.
We sell 2.37:1 screens to allow for this.
Just a thought
February 13th, 2007 at 2:36 pm
Carlton:
I have been reading the AVS thread on the Mits 46231 and found a link to your very helpful website here. Thanks for taking the time to put this together. I have found it to be very useful.
One small nitpick. On your Theatre Calculator spreadsheet, in the tab named Sheet 2, the word "noticeable" has been spelled incorrectly in cells 2C, 2E and 2G.
February 13th, 2007 at 3:48 pm
Darrin and John: Thanks for the feedback. Changes implemented.
March 15th, 2007 at 9:42 am
Hi,
I would like to know how to determine the best height to put my screen on a wall and why it's not part of your calculator ?
Thanks
March 19th, 2007 at 7:03 pm
Thank you for the great spreadsheet. I have one question. In the cell for projector brightness, should I enter the rated brightness or the brightness measured while playing from reviews.
Thanks
March 20th, 2007 at 7:31 am
Jack: Definitely use the measured / calibrated brightness. The inflated manufacturer specification figures do not represent real world performance.
April 4th, 2007 at 5:52 am
The 4:3 aspectratio won't work? Spreadsheet gives no value ex. fo Screen Brightness1 (projectors only) #! foot-Lamberts #! cd/m2
April 4th, 2007 at 7:29 am
Tjm: The 1.33:1 (4:3) aspect ratio is working fine for me. You probably have a blank cell cell or missing input. You can't leave any of the input boxes blank. Try re-downloading the spreadsheet if you can't get yours corrected.
April 8th, 2007 at 8:10 am
Just wanted to add my thanks for a great resource in the spreadsheet. Any chance of adding a 1.33 anamorphic lens option (eg ISCO III) to the sheet?
Cheers,
Mark
April 8th, 2007 at 4:45 pm
Mark_H: That capability is already there (indirectly). Enter the native resolution of your 16:9 projector and then select 2.37:1 as the aspect ratio. The only thing it will not do is compute the new throw ratios (with the lens) based on the original projector throw ratios.
April 10th, 2007 at 12:27 pm
The most recent changes in the revision history say "16-Feb-2006", but it should be "2007".
April 10th, 2007 at 12:33 pm
Atamido: Thanks, fixed!
April 30th, 2007 at 2:53 am
good tool,but may you please give a Chinese edition?
B'rgds
Bill
April 30th, 2007 at 7:26 am
Sorry, no plans for a Chinese edition. I don't speak Mandarin and can't enter pinyin characters. Additionally, maintaining two versions is more than I'd want to take-on.
May 17th, 2007 at 10:25 am
Thanks, I was wondering how to negotiate a maze of facors as I try and setup a media room for the viewing of my photography - this is perfect! You're a practical genious, thanks for distributing it.
May 27th, 2007 at 7:03 pm
The 4:3 aspect setting does not work correctly for me either. I just downloaded the spreadheet. Choosing 4:3 aspect ratio, screen height is calculated as zero. It will stay at zero even if you change the aspect ratio back to the original or another value. And some other values in the spreadsheet are #VALUE! when changing to other aspect ratio's after chosing 4:3.
June 15th, 2007 at 10:43 am
Great Job!!! I Just wanted to say thanks. Your calculator was very helpful!!
June 18th, 2007 at 3:44 pm
Very good stuff! It's exactly what I was looking for… Let me see if I get it: for a 37" TV HDMI, my actual viewing distance (9-10 feet) is a few longer? Thanks!
July 4th, 2007 at 1:26 am
Hey!
I just looked at your calculator, and it's a great tool. Made me realize I can use it to persuade the wife we need to move our 40"LCD ALOT closer, as I've been arguing for a year now!
Anyways, some of the aspect ratios don't work for me, and I think it's because we here use a ',' as decimal delimiter, and your sheet seem to use '.'. I'll work on it a little and try to come up with a clever solution. :o)
July 9th, 2007 at 2:14 am
I had to say thanks for creating by far the best single resource for home theater design that I can find. And being an Excel geek myself I can appreciate the thought and effort that went into creating the spreadsheet. Thanks for sharing with everyone!
July 20th, 2007 at 2:55 pm
A new version of the calculator has been posted; here are the details:
Version 3.5 - 20-July-2007: 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.
July 21st, 2007 at 12:58 am
Tested it, and it seems to be working flawlessly now. Thanks alot! :o)
July 22nd, 2007 at 8:39 am
I just updated the Home Theater Calculator to estimate visual acuity viewing distances based on the eyesight of the viewer:
Version 3.6 - 21-July-2007: 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.
September 22nd, 2007 at 6:09 pm
Carlton,
I am looking to build a high end home theater with a room 31 feet deep by 21 feet wide by 13 feet tall. I will have three rows of seating. The 1st will be sofa seating, the 2nd will be recliners and the 3rd will be bar seating.
I am looking to have as wide a screen as possible so that I can have complete immerserion when viewing film. I am looking to use four way masking with a 2 to 1 aspect ratio.
The projector would be would be mounted in a projection room and be a top of the line unit budgeted at $50,000+.
What would be the largest size screen you
think the room can handle.
Thanks for you time and help.
September 22nd, 2007 at 9:51 pm
That's a big room and it needs a big screen. It somewhat depends on which row is your primary row and how close it is to the screen. If you want to use all 3 row and have it be as immersive as possible, you need a very big screen (133+ inches). I think it really comes down to what your projector is capable of handling — it will need to be very bright for a screen this large.
I'd suggest a 2.35:1 screen. This is also known as a constant height setup. This, combined with a lens that converts a 16:9 (1.78:1) projector into a 2.35:1 projector is the way to go. The setup is becoming very popular in high-end home theaters and many projectors / image processors are now supporting it.
I don't have masking on my screen. I was initially going to add it but found I didn't really need it; the extra screen space was barely noticeable. If you do decide on masking, with a 2.35:1 screen, you would side-masking only. Thus the name "constant height." Good luck!
September 23rd, 2007 at 9:05 am
We are looking to buy a wall-mounted HD TV for an 11' x 14' bedroom that we are converting into a TV watching room. What is the best size for the TV knowing that we are probably 9' away and the room is only 14' in length?
Do 1080s or 720s come into play then?
September 23rd, 2007 at 5:56 pm
Dave S: My best advise is to enter your room info into the spreadsheet. It will answer all of your questions.
October 4th, 2007 at 2:55 pm
Hi
I am planning to have a 110" wide 2.35 screen. But there are no 2.35 projectors. Only 16:9 projectors are available and ProjectorCentral.com website provides manufacturers projection calculator based on 16:9 projectors. So will the amount of brigtness (in lumens) recommended for a 110" wide 16:9 screen be the same for 110" wide 2.35 screen. Please let me know.
-Venkat
October 4th, 2007 at 3:04 pm
Venkat: If you want to you a 2.35:1 screen, you'll have to use a 16:9 (1.78:1) projector and an anamorphic lens to stretch the image sideways. You'll need to make sure the video processor (either internal to the projector or an external processor) can handle the required format conversion.
Brightness is brightness. The light output of the projector divided by the area of the screen being illuminated gives screen brightness. Use the spreadsheet, enter your screen dimensions, and see what your required brightness is. Then go out and find a projector that has the required brightness and can handle a 2.35:1 converter lens.
October 4th, 2007 at 8:45 pm
Thanks a lot Carlton.
-Venkat
October 13th, 2007 at 7:43 pm
Hello,
I just purchased a Panasonic PT-AX100U. The projector is rear-shelf positioned about 11 to 12 feet away from screen. It can display a 110 inch diagonal with 16:9 format. The seating distance from eye to wall is around 11 feet.
Question…are there disadvantages from having that large of screen with being only 11 feet away? The picture looks fine on the wall now. (have not purchased screen yet). Is it too large to effectively enjoy a movie and be able to focus and see the whole picture without having to look around the screen? The recommended distance charts seem to make the screen way too small for a 11 foot viewing distance.
Michae M
October 14th, 2007 at 9:58 pm
Looking at the results for a 110" diagonal screen at 11' viewing distance, that is an ideal setup. You definitely don't want to go any smaller than that. You could maybe go larger but brightness will drop off and that can be an issue. Also, if a screen is too large, you can start to notice resolution deficiencies. You need to make sure you get a screen large enough to at least meet the THX field-of-view guidelines, going larger won't hurt but isn't necessary.
November 20th, 2007 at 6:55 pm
Thats a pretty informative spreadsheet, but I have some questions on throw distance. I am planning my first projector install. I have a room that is 19.5'x14' and I want at least a 120" diagonal screen to cover 3 windows. I have some limitations on the ceiling mount(cathederal ceiling and a fan) and would like to put the projector on the back wall. It looks like on your chart I will either have to size up the screen or move the projector forward. Looking at 1080p projectors. Any suggestions?
December 16th, 2007 at 9:26 am
Hey Carlton, love the calc
I've got a small request though; would it be possible to add 1.25 (5/4 AR) to your next revision; I had a need to work out some the sizes on some 17 & 19" LCD Monitors and an old Sun 21" (All 1280×1024 Resolution)
Cheers
December 16th, 2007 at 11:10 am
Does your home theater calculator take into consideration that after several hundred hours of use, a projector's brightness will dim say 35 - 50% depending on the projector
December 19th, 2007 at 12:41 am
Great calculator Carlton. I have bedrooms where I am struggling with "correct" size and resolution. First is my bedroom, viewing distance will be approx. 12' from the TV. I'm leaning towards 50" plasma at 720p because my understanding is 42" may be too small at that distance and 1080p wont really become noticeable. Am I correct in those thoughts? Second, is my basement where I will be sitting from multiple angles and multiple distances but mostly 6-10 ft away. I am considering three options mainly for HD sports and Blu-Ray: Samsung 5084 (1080p plasma), Samsung 5271 w/ 120 Hz(1080p LCD), and Ssamsung 5884 (1080p plasma). I am in analysis paralysis and could really use your expert opinion. I am happy with the picture on all of them at the local BB store, I just can't make up my mind on what is best for my exact situation.
December 21st, 2007 at 12:42 pm
Carlton, I think that your calculator has what I need but I don't understand the language, 'throw distance' etc to figure it out. I am working on a room that could have someone seated 42 feet away from the projection surface to listen to a presentation and view a powerpoint and other non-video images. How big should the images be? I do not have a projector selected yet.
February 20th, 2008 at 4:07 pm
What if I have soft cushions? Then my distence will vary. Didn't think of that did ya?
February 20th, 2008 at 4:46 pm
I guess I'll need to add a cushion softness coefficient.
March 28th, 2008 at 2:47 pm
You might want to add these viewing distance standards, too:
Reference Viewing Distance specified by SMPTE (3 Picture Heights and AR=16:9 or lower)
Minimum Viewing Distance recommended to hide the "Screen Door Effect" where PPD=30
Maximum Viewing Distance recommended by THX for CinemaScope (HVA=36° and AR=2.39:1 letterboxed)
Ideal Viewing Distance specified by 20th Century Fox for CinemaScope (HVA=45° and AR=2.39:1 letterboxed)
Minimum Viewing Distance specified by SMPTE (2 Picture Heights and AR=16:9 or lower)
Source:
http://home1.gte.net/res18h39/calculator.htm
This diagram shows nicely, as well:
http://home1.gte.net/res18h39/allscope.gif
This tends to jive with what most people find an ideal seating distance (1.2x-1.3x 2.35 width) for maximum involvement and immersion when it comes to dedicated home theaters with 2.35 screens - based on what I've witnessed on AVS Forums over a period of quite some time.
March 28th, 2008 at 2:52 pm
Oh, I should also note that most people with 20/20 vision find visual acuity for maximum resolvable content for moving images is around 30-40 pixels per degree (approx factor of .5 to .66) - might be worthwhile to add this distance, as well.
April 20th, 2008 at 4:10 pm
Just to clarify, for the universal projector throw distance calculator, is the screen width horizontal or diagonal? and Thanks for this cool tool.
April 21st, 2008 at 6:40 am
JJ: It's horizontal screen width for the universal throw distance calculator.
May 7th, 2008 at 8:42 am
Hello
i would like to know. do you have a calulator to estimate the viewing distance and resolution for a soccer field…..
Help please?
May 7th, 2008 at 10:11 am
Gladys: The same calculator should work. Just enter screen size and viewing distance. The field-of-view would be much smaller because people would be farther away, but the spreadsheet will tell you if the viewer at a certain distance needs more or less resolution than what you've entered in the top section of the spreadsheet. Keep changing the resolution until you find one that is appropriate.
June 14th, 2008 at 8:40 am
Carlton, Thanks for this great tool. I just have a question for you. I don't really understand the calculation in the final portion of the table for the platform height for the second row. Is the back row seated eye height supposed to be measure from the floor or from the platform level? If my first row seated eye height is 40 inches from the floor and my platform for the second row is 10" height. The back row seated eye height should be 40" + 10" for a total of 51", assuming that both seats are identical. However in the table I get a negative value for the back row platform height when I enter these values.
June 14th, 2008 at 9:28 am
Pedro: I've updated the spreadsheet. It should address all of your questions. Here is a list of the changes:
Version 3.7 - 14-June-2008: 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.
June 14th, 2008 at 5:45 pm
Thanks Carlon.
June 26th, 2008 at 9:34 pm
Brilliant, thanks! If I can say so, I ran your calculations by a customer service rep at Panosonic and they agreed that I only needed a 42" 720p for my family room, kudos to both of you, they could have easily upsold me.