Screen Size Calculator: What are the Dimensions of a TV Screen?

TV, computer, and smartphone screens are sized by their diagonal lengths. But have you ever wondered how wide and tall a 40-inch TV screen actually is? Perhaps you’re looking for a place to hang it on your wall but can’t figure out how much space to allocate for it.

Quick Link to the Screen Size Calculators

If that’s the case, you’ve come to the right place. Today, we’re going to show you how you can determine the exact dimensions of your screen.


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Aspect Ratio

First things first, we have to talk about aspect ratios.

The aspect ratio refers to the height and width of a rectangular display, which is expressed in ratio terms. The ratio value is used to determine the size of any electronic with a screen, including TVs, laptops, tablets, and even projectors. However, the aspect ratio figure is not directly correlated to the size of the screen—it merely explains the screen’s proportions.

What Is an X-inch Phone/Tablet/Monitor/TV/Laptop/Etc.?

As we stated earlier, manufacturers will market their products based on the diagonal lengths of their screens. So, say you want to mount a TV that measures 32 inches diagonally. The 32 inches refers to the distance from one corner of the screen and the opposite corner.

The screen size really doesn’t help you determine how much pocket space the tablet will take up. And it can be incredibly more challenging to figure out how much wall space a large-screen TV will take up simply by looking at diagonal measurement.

The most common screen size is 15 to 15.6 inches for laptops
The most common screen size is 15 to 15.6 inches for laptops

Screen Size Calculator

So, let’s say you want to mount a 32-inch TV with a 16:9 aspect ratio. What are the TV’s screen’s dimensions and how much space will it take?

There are three formulas that we need to use to determine the actual dimensions of the screen, which are as follows:

  • Diagonal² = Height² + Width2
  • Aspect Ratio = Width ÷ Height
  • Screen Area = Width × Height

However, we will have to adjust the formulas to find out the height and width of the TV screen.
First, let’s calculate the screen’s height:

  • Height = Diagonal ÷ √(Aspect Ratio² + 1)
  • Height = 32 ÷ √((16:9)² + 1))
  • Height = 32 ÷ √(3.16 + 1)
  • Height = 32 ÷ √(4.16)
  • Height = 32 ÷ 2.04
  • Height = 15.68 inches

After knowing the height, we can know calculate the screen’s width:

Width = Aspect Ratio × Height
Width = (16:9) × 15.69
Width = 1.78 × 15.69
Width = 27.88

And finally, we can calculate how much space the screen takes by using multiplying the screen’s height and width:

Area = Height × Width
Area = 15.69 × 27.89
Area = 437.15 square inches

As you can see, there’s a lot of calculating that goes into determining the dimensions and area of your screen.

Ratio Screen Size Calculator

But we’ve made things easier for you by preparing a screen size calculator. It consists of 3 calculators for 3 different aspect ratios (16:9, 21:9, and 4:3), which are the most common aspect ratios.

16:9 Ratio Screen Size Calculator

21:9 Ratio Screen Size Calculator

4:3 Ratio Screen Size Calculator

Screen Size vs. Resolution

So, is screen size directly correlated to resolution? Do wide-screen gadgets automatically have better picture quality than those with smaller screens?
While this may be the case 99% of the time, screen size actually has very little to do with resolution and vice versa.

Screen size refers to the physical size (expressed in inches) of the screen, whereas resolution refers to how many pixels there are. To demonstrate, a 2021 iPhone 13 Pro has a 6.1-inch screen with a resolution of 1170 × 2532 pixels (a 19.5:9 aspect ratio for those that are keeping track).

Meanwhile, an older Sony Xperia XZ Premium has a 5.46-inch screen with a resolution of 2160 × 3840 pixels (16:9 aspect ratio).

The latter smartphone would have an objectively better-looking screen than the former simply due to the fact that there are more pixels.

Screen Size vs. Resolution

What Is Pixel Density?

Pixel density has more of a correlation to resolution than screen size. In simple terms, pixel density refers to how many pixels are packed into a given area—typically one square inch, which is known as pixels per inch (PPI).

The more pixels there are on the screen, the more difficult it will be for a viewer to notice individual pixels. Using the same smartphone models from earlier, the iPhone has a PPI rating of 460, while the Sony smartphone is nearly twice that at 807 PPI.

Generally speaking, the larger the screen, the lower the PPI rating. For instance, a 1080p full-HD TV measuring 24 inches will have around 91 PPI, whereas the same resolution but on a 27-inch screen will have a lower rating of around 82 PPI.

This is just something to think about if you’re planning on getting a wide-screen TV or monitor to mount on your wall.

What Is Pixel Density


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About the author

Hi I’m Alexander, founder of HouseholdMe.com and I’d like to say thank you for dropping by. Like most of you, the first thing I look at before buying something online is reviews or buying guides. By reading what other people say will help me gauge whether or not a product is good or not.  I am trying to help people find answers, solve problems, and get inspired.

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