All about Flat Screen TVs

How to know TV size for example 42 inch TV dimensions length and width

When we talk about TV size, it is the diagonal length of the TV screen from corner to corner of the visible screen area, excluding the side frames. The picture here shows how a 42 inch TV screen size is measured. Since one inch is equal to 2.54 cms (centimeters), the Metric TV size will be 107cms. The actual measurement may differ a little, but the decimal points are rounded off.

Picture of how the size of a TV is measured
42 inch TV dimension
How to calculate side width and height of a TV screen
TV screen width height calculation

TV normally comes in the following standard sizes (" =inches) 22", 26", 32", 37", 40", 42", 46", 50”, 55", 60" 65" and higher. The corresponding metric size of the TV in centimeters are 56, 65, 81, 94, 102,107, 117, 127,140, 152 and 165 cms respectively.

How to calculate width and height of TV screen

Without actually measuring the TV width and height it is possible to calculate the width (b) and height (a) of TV screen just by knowing the diagonal size of the TV. This makes it possible to kow the approximate width and height of a TV before even actually buying it. To make the calculations of TV width and height, we make use of the Pythagoras method as shown in the picture here. The HDTV widescreen aspect ratio of 16:9 is used. By knowing beforehand the width and height of TV you can know for sure what size TV will fit in your cabinet or make enough wall space to mount the TV on the wall. Thus a 40 inch HDTV will be 35 inches wide and 20 inches tall. Similarly actual size of 55 inch TV length and width will be 47.9 inch or 121.7cm wide and 27.0 inch or 68.6 cm tall.

Standard TV sizes width height
Standard TV SizeWidthHeight

These TV size calculations can also help you to calculate size of 4:3 pictures on 16:9 TV.

Let us assume you have 32 inch 16:9 LCD TV and you want to calculate the size of a 4:3 picture viewed in the 4:3 mode view of the 32" 16:9 television. Using the Pythagoras Theorem the diagonal d=32 inch, therefore the height 'a' in the figure is calculated as 15.75 inches. Since ratio is 4:3 the width will be 21 inches. So the 4:3 diagonal size is 26.2 inches on the 32" 16:9 TV. That means the TV 4:3 natural picture without zooming you see on a 32 inch 16:9 widescreen TV is equivalent to a 26 inch CRT TV with a 4:3 ratio. For a 40 inch 16:9 widescreen HDTV, the 4:3 natural picture without zooming will be the equivalent of watching it on a 33 inch 4:3 TV.

How far to sit from HDTV, Right size TV for viewing distance

There is an ideal distance between TV and sofa seating and this seating distance between Sofa and TV will depend on the size of TV. To know the size of TV to buy, you should first decide where the TV will be placed in the room and then measure how far to sit from LED HDTV or whatever type of TV you plan to buy. Then use the TV size to minimum watching distance chart given below to get an idea of the best size TV to buy.

The table chart below compares TV size to the minimum sitting distance required to watch TV. The TV viewing distance is the distance from the TV screen to the approximate position of your eyes when viewing TV regularly.

TV size and viewing distance are important factors to decide on the size of TV to buy. If you sit too close to a LED HDTV you will see the pixilation squares on the TV screen. As a general rule the TV to sofa distance ratio or HDTV viewing distance is 1.5 times the screen’s diagonal measurement. Thus the best distance to sit from a 60 inch HDTV will be 90 inches or 7.5 feet (about 2.3 meters) from the TV screen

There are no official bodies, as yet, to recommend viewing distance for TV size. One of the leading Companies in the world of surround sound, THX, recommends viewing distance as follows.

To quote from the THX website:

How do you calculate the best seat-to-screen distance for a TV or projection screen? Divide the size of your screen by .84 (screen size is measured diagonally). For example, a 65-inch TV divided by .84 equals a 77-inch viewing distance (6.5 feet).
If your HDTV is going in a living room with limited space, THX recommends the following:
35 inch class TV = 3.5-5 feet away
40 inch class TV = 4-6 feet away
50 inch class TV = 5-7.5 feet away
60 inch class TV = 6-9 feet way
It might seem that THX is recommending a very large screen size for your room. But, it’s important to note two things:
1) THX screen size recommendations are based on recreating an immersive cinematic experience, and 2) the biggest complaint among TV buyers is that they wish they had bought a bigger set.

The THX TV viewing calculation of dividing TV size by 0.84 (which in effect is multiplying TV size by 1.19) may be very good for the latest generation of Ultra HDTV, but we maintain that the minimum viewing distance for regular HDTV should be 1.5 times the screen size of HDTV. Sitting closer to HDTV than this 1.5 ratio may make you notice the little square pixelation on the screen.

The TV Size to Viewing Distance chart below is about how close you can sit when watching TV and is based on a factor of 1.5 TV size for HDTV and a factor of 1.19 (divide by 0.84) as recommended by THX for watching Ultra HDTV. The distances mentioned in the chart are the closest distance to watch TV for HDTV or Ultra HDTV.

UHDTV / HDTV minimum distance to watch TV
TV SizeHDTV Minimum DistanceUHDTV Minimum Distance

TV side Viewing Angle, TV Viewing from the side

TV Viewing Angle

TV Viewing Angle explained as how far to the left or right you can sit to watch TV from the sides. If you are sitting straight in front, you are sitting at Zero degrees, as you go right or left to the side of the TV, the angle increases to 90 degrees when you reach a point parallel to the TV. Most TV manufacturers specify the total viewing angle, which is the angle from the farthest left to the furthest right the TV can be viewed, as is shown in the figure here. The maximum possible in such a case will be 180 degrees, which is 90+90 degrees. The best position to watch TV will be straight in front of the TV which will be zero degrees.

Best Height to watch TV, best height to mount TV on wall

The best TV height is eye level height. The middle of the TV screen should be below your eye level
Best height for TV at eye level

The best TV height is eye level height. The middle of the TV screen should be below your eye level, one third of the TV height from top down as shown in the picture on the left. To put it more clearly divide the TV height by 3. When you sit to watch TV, your eye level should be one third of the TV height down from the top of the TV. The figure on the left shows how.

Our eyes are more comfortable looking slightly down than looking up, that is why the TV should be placed slightly below eye level. It is recommended that neither the top nor the bottom of the TV should be more than 15 degrees from the horizontal plane of your eye level. If you are watching TV lying down, then the TV can be mounted higher up for ease of TV viewing, but make sure that theTV is tilted down so that your line of vision falls at 90 degrees on the TV screen plane.

Aspect Ratio of TV Screen

This is the ratio between the width and height of the visible TV screen. HD TV has an aspect ratio of 16:9, CRT TV has an Aspect Ratio of 4:3. As a TV Aspect Ratio guide we will make a TV Aspect Ratio comparison of common TV formats like 640:480 which is the same as 4:3, similarly 1280:720 and 1920:1080 works out to 16:9. These are not the only TV aspect ratios, there are some other TV Aspect Ratios which are not so common like the 16:9 and 4:3.

Many countries still transmit TV signals in the 4:3 format. When you view a normal 4:3 format movie in 16:9 format, the picture stretches sideways, making people and objects look fatter. You can correct this problem by changing the aspect ratio setting on your TV and watching it in the native 4:3 format, or for a wider view with less distortion on a 14:9 format.

When a 16:9 movie is squeezed and compressed into 4:3 format movie, people and objects look very thin. When widescreen video images are squeezed to fit a narrower aspect ratio it is called 'Anamorphic Video'. When expanded into 16:9 ratio they look normal. In order to save bandwidth while transmitting TV stations broadcast widescreen movies in the 4:3 format and the viewer can expand it into the 16:9 format and watch the movie normally.

Buying TV online

These days buying a TV on line makes more sense, because of the many advantages. You get to buy the TV without much hassle online and the courier Company delivers to your door. If you want installation, it can usually be ordered online at the time of purchase, most of the time included in the price or there may be a very small extra charge. The price of TVs online from Amazon will be cheaper than what is available in your local stores. Service and Warranty are as good as or even better than if you bought it at a local store. The best part is that in case you are not satisfied with the TV, you can return it and get full refund and Amazon will arrange for the courier to pick up the returned item from you.

Links to buy TV online from Amazon

This is the Link to buy TV online from Amazon CANADA

This is the Link to buy TV online from Amazon INDIA

This is the Link to buy TV online from Amazon UK

This is the Link to buy TV online from Amazon USA


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