What Are The Standard 40 Inch Tv Dimensions?

Tv and screens are measured diagonally by consumers and manufacturers as well. The measurement of a Tv screen is measured from the top corner to the bottom corner on the opposite side. To understand 40-inch tv dimensions, you can use algebra and trigonometry to calculate the width and height of screens. Using mathematics you will get the dimensions slightly smaller than the screen because the output doesn’t contain the edges, which are also called bezels.

  • Across the diagonal of the screen, the 40-inch TV dimensions are 40 inches.
  • The 40-inch screen with an aspect ratio of 16:9 has a width of 34.9 inches and a height of 15.7 inches.
  • The width of the bezel varies depending on the model.

How to measure a TV screen and why does screen size matter?

40 Inch Tv Dimensions

In the details of the product box, TV screen dimensions are always listed. As I have mentioned above the 40’’ TV is 40 inches diagonally from one corner to another corner. In this dimension, the bezel width is ignored. The sizes of screens do not vary around the globe. The difference, if any, is only half an inch.

What are aspect ratios?

Let’s understand the aspect ratio first before we jump into the calculations of dimension.

The ratio of a display screen is shown in a (width:height) manner. The aspect ratio displays the width and height of a screen. The most common aspect ratio is 16:9, although 4:3 and 21:9 aspect ratios are also widely used in the industry.

The aspect ratio is used to show the proportion of the screen. It is not directly related to the screen size. In order to calculate the total area of the screen, the aspect ratio is used to determine the width and height of the TV screen.

Standard 40-inch TV dimensions:

40 Inch Tv Dimensions

You can figure out the height and width of the Tv with algebra. Let me give you a quick example if the screen is 40-inches diagonal and the aspect ratio is 16:9. Using Pythagorean theory, you can calculate one unit in inches and multiply it by 16 to get the screen’s width and by 9 to get its height. You don’t have to learn the mathematical theory by yourself; you can use any online website to calculate it for you, and most items have their dimensions listed in their descriptions.

As an example, the 40-inch Samsung 1080p HDTV has dimensions of 36.1 inches in width and 21 inches in height without the stand, according to its description.


Here is the formula to calculate the screen dimensions using the aspect ratio.

H = D ÷ √(AR2 + 1)

With the above formula, the height of a 40” tv screen can be calculated, and its aspect ratio is 16:9.

  • H = 40 ÷ √((16:9)2 + 1))
  • H = 40 ÷ √(3.16 + 1)
  • H = 40 ÷ √(4.16)
  • H = 40 ÷ 2.04
  • H = 15.7 inches
  • H = 39.8 centimeters

We have calculated the height of the screen. Now let’s calculate the width of the screen. Here is the formula for width.

W = AR × H

So, here’s the solution:

  • W = (16:9) × 15.7
  • W = 1.8 × 15.7
  • W = 28.2 inches
  • W = 71.6 centimeters

The width and height of the 40-inch, 16:9 screen are 28.2 inches and 15.7 inches, respectively. Now let’s calculate the total area of the screen. To calculate this we have to multiply the width and height.

  • A = W × H
  • A = 28.2 × 15.7
  • A = 442.7 square inches
  • A = 1,124.5 square centimeters

The diagonal measurement and aspect ratio of the screen are listed on the packaging box of the television, so calculating the width, height, and the total is pretty straightforward.

What is the resolution on Tv screens?

There is a big misconception in the market about TV size and its resolution. People assume that the bigger the TV, the better the resolution. This seems like the right expectation from TV companies but this is not logically right. Because resolution means how many pixels are packed into the screen. 

Assume one TV screen is 32 inches with a resolution of 1920 x 1080 pixels and the other is 40 inches with a resolution of 1280 x 720 pixels. In this example, you can see that the smaller TV has a higher resolution than the larger one.

What is pixel density in Tv screens?

pixel density in Tv screens

Pixels packed into a specific area of a tv screen are called pixel density. This area is usually measured in square inches, also called PPI or pixels per inch.

The pixel density is used to assess screen quality. The more pixels are jammed into a square inch, the harder it will be for consumers to notice each pixel.

The PPI can be calculated using the following formula.

Diagonal­­Pixels = √(WidthPixels2 × HeightPixels2)

So, as I showed two different resolutions in the above example (1080p 32-inch TV vs. 720p 40-inch TV), we would get:

  • 32-inch TV Diagonal­­Pixels  = √(19202 × 10802)
  • 32-inch TV Diagonal­­Pixels  = √(3,686,400 × 1,166,400)
  • 32-inch TV Diagonal­­Pixels  = √4,852,800
  • 32-inch TV Diagonal­­Pixels  = 2,202.9 pixels
  • 40-inch TV Diagonal­­Pixels  = √(12802 × 7202)
  • 40-inch TV Diagonal­­Pixels  = √(1,368,400 × 518,400)
  • 40-inch TV Diagonal­­Pixels  = √2,156,800
  • 40-inch TV Diagonal­­Pixels  = 1,468.6 pixels

Now let’s compare pixel densities in square inches.

  • Pixel Density = DiagonalPixels ÷ DiagonalInches
  • 32-inch TV Pixel Density = 2,202.9 ÷ 32
  • 32-inch TV Pixel Density = 68.8
  • 40-inch TV Pixel Density = 1,468.6 ÷ 40
  • 40-inch TV Pixel Density = 36.7

Now see in centimeters,

  • Pixel Density = DiagonalPixels ÷ DiagonalCentimeters
  • 32-inch TV Pixel Density = 2,202.9 ÷ 81.3
  • 32-inch TV Pixel Density = 27.1
  • 40-inch TV Pixel Density = 1,468.6 ÷ 101.6
  • 40-inch TV Pixel Density = 14.5

We can also get an idea about the picture quality of the screen using the pixel density of the screen. 

Final thoughts:

In this post, I have discussed the 40-inch TV dimensions and described the aspect ratio, resolution, and pixel density. I also have used the formulas to calculate dimensions on their own so they can get a clear idea before they choose any TV screen.

Just a reminder, a 40-inch TV screen has an aspect ratio of 16:9, 28.2 inches in width, and 15.7 inches in height. The 40-inch TV screen measures 40 inches from one corner to another corner diagonally.

If you still have queries or suggestions do not hesitate to comment below.

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