Ambiguity of TV screen size to be said in its diagonal distance !

If we go to an electronic market place, we are introduced to the proper TV model and its size which is shown in its screen diagonal distance.

But we just want to know TV's width and height to find out the proper size for our living room condition.

But TV industry has used this screen diagonal size method worldwidely and it would not be changed soon.

Now TV screen size is getting bigger and bigger by introducing HDTV, UHD TV, etc. Therefore we are frequently questioned which size of TV is fit to our living room condition. We just need to know the optimal viewing distance per TV screen size.

How do we calculate TV size from its diagonal distance ? What is the optimal viewing distance in each TV diagonal distance ?

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Calculation of TV size and optimal viewing distance !

For your convenience, I coded automatic calculation software for TV size and its optimal viewing distance as shown in below,.

Enter TV screen size at the text box named "TV diagonal screen size(Inches)". Then choose your TV type like "Wide screen TV..." or "Regular old TV...".

Recent released TV which has wider width(ratio 16:9) is wide screen TV. Regular old TV shapes like a perfect square(ratio 4:3).

Then click "Calc" button and results will be shown in below. You could find out width, height, display area of TV from diagonal screen size. You can also get the optimal viewing distance.

Aspect ratio difference in TV type

Width and height of TV can be different depend on what aspect ratio it has. Regular old TV has 4:3 ratio(Width:Height). Therefore it seems to be a perfect square.

But wide screen TV who can fully support HDTV(High Definition TV) has 16:9 ratio.

To get the correct width, height of TV screen size, you should choose TV type well.

Equation to calculate TV size.

You can use next equation to calculate width, height of TV screen. "d" is TV's diagonal screen size in inches. "r" is ratio of TV screen's width and height. "r" of 16:9 wide screen TV is 1.77 while 4:3 is 1.33.


You don't worry about the calculation of this. My software put on above is doing this calculation automatically upon your input value.

Optimal viewing distance

TV's resolution should be higher to view it in short distance. If it is not that much level, you could see only dot instead of image or video on the TV scrren.

Regular old TV who supports SD TV contents has lower resolution. Therefore minimum viewing distnace of regular old TV(4:3 ratio) can be 3 times of TV screen width, while maximum viewing distance is 6 times of TV screen width.

Wide screen TV is supporting HDTV contents having higher resolution. Therefore its optimal viewing distance is between 1.5 times and 3 times the screen's diagonal sreen size.

But this optimal distance is just based on the statistical data, and there might be personal variance. Therefore above optimal viewing distance is just for your reference.

I hope these information is helpful you to decide buying new TV for your living room condition.

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