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_v4.0.xls

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

Revision history:

  • Version 4.0 – 26-August-2008: Added Anamorphic (horizontal expansion) front projector lens option, which adjusts projector brightness and throw ratios when selected.
  • 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.
Written by on 2006-Nov-11, Last updated on: 2006-November-11 in: |


  • John says:

    Hi carton, thanks its really great to read your post a lots of information. I just started researching on this, we are building a dedicated home theater room with site of 15 X 24 feet. Just wonder what is the best fixed screen I can go with along with the projector you can recommend. 3 row, each of which are 5 feet apart. can you please help.

    • Carlton Bale says:

      John, with 3 rows, the first will be extremely close to the screen. Maybe too close. You should be ok with a 123-inch screen. JVC projectors are awesome, Sony and Epson are good alternatives.

  • muralidhar says:

    hello carlton
    I have a small room of size 10ft in width and 12ft in depth can I make a home theatre in this dimensions for a four seater pls suggest me weather to go for ohp or tv of which sizes

  • G R Malik says:

    i am using 325 inch diagonal screen (285 x 160 inch) first row is 28 feet away ,last row is 8t feet away, is it ideal screen size or what will be ideal screen size

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