Screen Size Calculator

The screen size calculator gives you precise calculations for the size of your device display. Estimate the perfect screen size for your TV, monitor, or mobile according to your entertainment requirements. 

Whether you want to calculate the flat or curved screen size, the calculator will get it done in less than a second. Experience the best view at an optimal distance from your sitting position.

Screen Size Concept – What Is My Screen Size?

“It is the length of the diagonal of a screen and is expressed in units of inches”

The size of a screen affects the visual experience. It gives you an idea of how large or small the content will look on a certain screen. 

When buying an electronic device like a TV, smartphone, or projector, you must have a sound knowledge of screen dimensions.

Knowing this value will help you purchase a device that fits best according to your viewing angles and distances.

Viewing Distance:

The following chart shows the optimal distance that you must consider for viewing your TV, home theater etc.

How To Calculate Screen Size?

If your goal is to do calculations by hand, you need to understand the following scenario:

For Flat Screen:

Whenever you calculate the screen size, keep in mind that it depends upon a couple of factors including:

• Aspect ratio (to calculate it, tap aspect ratio calculator)
• Screen Diagonal
• Screen Height
• Screen Width

Calculating screen size manually requires the following steps to understand:

Determine Aspect Ratio:

The aspect ratio is the ratio of the width and height of the screen and can be calculated with the help of the following equation:

Aspect Ratio = Width/Height

Screen Diagonal Calculations:

To calculate the diagonal of the screen, simply take a measuring tape and measure the distance from one upper corner of the screen to the opposite lower corner.

The mathematical formulas to calculate the screen diagonal are as under:

\(Diagonal^{2}=Height^{2}+Width^{2}\)

\(\text{Aspect Ratio}=\dfrac{Width}{height}\)

\(\ Screen\ Area =\ Width\times Height\)

See the following example to calculate the unknown measurements and size of the screen:

Example: 

Let’s suppose you have to find the size of a screen having an aspect ratio of 16:9 Find the unknown screen measurements and the screen size.

Case #1: When the Diagonal is 3 inches, how to measure monitor size?

Solution:

For monitor dimensions:

\(Aspect \ Ratio = \dfrac{Width}{Height}\)

\(AR = \dfrac{Width}{Height}\)

Height = AR x Width

\(Height = \dfrac{16}{9}*Width\)

Now put this value of height in the formula of diagonal

\(Diagonal^{2}=Height^{2}+Width^{2}\)

\(Diagonal^{2}=\ (\dfrac{9}{16})^{2}*Width^{2}+Width^{2}\)

\(Diagonal^{2}=\dfrac{81}{256}*Width^{2}+Width^{2}\)

\(Diagonal^{2}=\ (\dfrac{81}{256}+1)Width^{2}\)

\(Diagonal^{2}=(\dfrac{81}{256}+1)Width^{2}\)

\(Diagonal^{2}=(\dfrac{81+256}{256}+1)Width^{2}\)

\(Diagonal^{2}=(\dfrac{81+256}{256})Width^{2}\)

\(Diagonal^{2}=(\dfrac{337}{256})Width^{2}\)

To find width: 

\(\sqrt(Width^{2})=(\sqrt(\dfrac{256}{337})*Diagonal^{2})\)

\(\sqrt(Width^{2})=(\sqrt(\dfrac{256}{337})*{3}^{2})\)

\(Width = (\dfrac{16}{18.35})*3\)

Width = 2.615 inches

Calculating the height:

\(Height = \dfrac{16}{9}*Width\)

\(Height = \dfrac{16}{9}*2.615\)

Height = 1.47 inches

Screen Area = Width*Height

Screen Area = 2.615*1.47 = 3.89 

\(Screen\ Area  =\ 3.89\ inches^{2}\)

\(Screen \ Area  = 3.89 \ {inches}^{2}\)

Case #2: When only height is given as 3 inches, then how to measure screen size?

Solution:

\(AR = \dfrac{Width}{Height}\)

\(Width = \ AR*Height\)

\(Width = \dfrac{16}{9}*3\) = 5.3 icnhes

Put the value of width in the formula of diagonal:

\(\ Diagonal^{2}=Height^{2}+Width^{2}\)

\(\ Diagonal^{2}=\ {3}^{2}+{5.3}^{2}\)

\(\ Diagonal =\sqrt(3)^{2}+(5.3)^{2}\)

Diagonal = 6.09 inches

Screen Area = Width*Height

Screen Area = 5.3*3

\(\ Screen \ Area  = 16 \ {inches}^{2}\)

Case #3: When only width is given and its value is 3 inches

Solution:

\(Aspect \ Ratio = \dfrac{Width}{Height}\)

\(AR = \dfrac{Width}{Height}\)

\(Height = \dfrac{Width}{AR}\)

\(Height = \dfrac{Width}{\dfrac{16}{9}}\)

\(Height = \dfrac{Width}{16}*\frac{9}{1}\)

Height = 1.68 inches = 1.7 inches

Now find the width with the 

\(Diagonal=\dfrac{81}{256}*Width^{2}+Width^{2}\)

\(Diagonal=\sqrt(Width^{2}+Height^{2}\)

\(Diagonal=\sqrt(3)^{2}+(1.7)^{2}\)

\(Diagonal=\sqrt11.89\)

Diagonal = 3.45 inches

Screen Area = Width*Height

Screen Area = 1.7 x 3 

\(Screen \ Area  = 5.1 \ {inches}^{2}\)

For Curved Screen:

The formulas that are used to know the dimensions and the size of the curved screen are as follows:

\(\ Height =\dfrac{Diagonal}{\sqrt(AR^{2}+1)}\)

\(\ Length =\ AR(aspect\ ratio)\times height\)

\(\ Area =\  Width\times Height\)

If you have to find the unknown measurements of a curved screen, then you can use the above-mentioned formulas for the diagonal, width, and height and to find the additional factor which is the base depth, use the following formula:

Base Depth = radius × (1 – cos(length / (2 × radius)))

FAQ’s:

What Factors Should I Consider When Choosing The Screen Size?

You should consider the following factors while choosing a screen size:

• Usage
• Resolution
• Screen Size
• Refresh Rate
• Budget
• Lighting

What Size Is A 120 Screen?

If the diagonal of the screen is 120 inches with an aspect ratio of 16:9 then the screen dimensions will be 59” H x 105” W. 

References:

Wikihow.com: Measure Monitor Size.