## Screen Size and Seating Distance

Is there a site that can help determine the right screen size for a given seating distance? In my case, the distance from my couch to the TV is 7 feet.

Emery Walker

The site I use for that purpose is here. When you open this page, scroll down to the Viewing Distance Calculator section, enter your seating distance in feet, and click on the 16:9 button to specify the screen shape. Then, click on the Calculate button and look at the Screen Size section. For your seating distance of 7 feet, you want a 16:9 screen that measures about 52 inches diagonally to achieve the minimum SMPTE-recommended viewing angle of 30 degrees or about 63 inches for the THX-recommended viewing angle of 36 degrees.

The optimum screen size for a given seating distance is much larger than most people think. Most folks sit farther from the screen than you do—typically 10 feet or more—and they buy TVs with much smaller screens than they should—often 42 to 50 inches, which is smaller than you should get even at 7 feet. So my advice to all TV shoppers is to buy a larger screen than they are probably considering and to use the site linked above to determine the best screen size for their seating distance.

You can also use this calculator if you already have a TV and want to know the optimum seating distance for that screen size. For example, let's say you have a 50-inch, 16:9 TV. Enter that info into the corresponding fields and click on the Calculate button. As you can see above, the maximum SMPTE-recommended seating distance is 6.8 feet, which yields a viewing angle of 30 degrees. The maximum THX-recommended distance is 7.9 feet for a viewing angle of 26 degrees, and the optimum THX-recommended distance is 5.6 feet for a viewing angle of 36 degrees.

Interestingly, this calculator also provides the maximum viewing distance based on visual acuity—that is, the distance beyond which you cannot see all the detail in the picture because of the limitations of the human visual system. In the case of a 50-inch, 16:9, 1920x1080 display, that distance is 6.5 feet.

My seating is anywhere from 6 to 8 ft from my 46" plasma and that screen size works out very well for me. I have a very small den 10X20 Ft and any thing much larger would overwhelm the room. That's not saying larger wouldn't be better, but your over all room size among other things, should be taken into consideration. Also, the SMPTE and THX recommendations may be worth considering in a perfect world where you have perfect picture quality, but keep in mind, due to data compression and other HDTV anomalies, certain artifacts such as video noise and banding will be more noticeable the closer you get and the bigger the screen.

Ian

This is great! Thanks!

For those who are more visually inclined... here's another link to a site with a calculator that let's you input different screen sizes and it will visually show you the recommended seating distances:

http://www.htmart.com/pages.php?pageid=16

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