How to Measure a Monitor Screen on Computer (4 Easy Methods)

Here is a guide on How to Measure a Monitor Screen (Desktop, Laptop, TV) by using any of the 4 Methods.

Thesedays, you will find monitors with different screen sizes. And many people don’t know how to measure a monitor screen. 

Different Monitors have different Aspect Ratio. The old monitors used to be in a 4:3 Ratio. Therefore, they were square-shaped. Thesedays, you can find most Monitors with a 16:9 or 16:10 or 21:9 Ratio. 

So, the length and breadth of the Monitor vary depending on the Aspect Ratio. Therefore, we do not measure a Monitor using its length or width.

How to Measure a Monitor Screen:

There are multiple ways of measuring a Monitor Screen.

1. How to Measure a Monitor Screen Physically:

The Best and Most Effective method is to measure the Monitor Screen using a measuring tape. You should not measure the length or width of the screen. You should take the measuring tape and measure the screen diagonally. (as you can see in the below images)

Note: You should only measure the screen. Do not measure the bezel (plastic frame of the monitor). 

No matter which aspect ratio the Monitor is, measuring the Dialognal Length will tell you the size of the screen.

2. Look at Laptop/Monitor Model Number

You can look at the Model Number to measure the Laptop Monitor Screen Size. 

The Laptop Acer Aspire 5 A515 has a screen size of 15 inches.

Another Example is the BENQ Monitor. The Model GW2480 Black has a 24″ Screen Size. 

Note: Most Monitor and Laptop manufacturers include the Screen Size in the Model Name. But, not all. So, the first method is more effective.

How to Find the Monitor Model Number?

You can find the Model Number on the Product Box. However, if you couldn’t find the Product Box, you can find the Model Number by following the guide below.

• Go to Windows Settings & Open the option System.
• Open the Display Menu, and Scroll down to find Advanced Display Settings.
• Here you can see the Product Model Number. 

• In my case, I have a BenQ GW2480, which has 24 inches screen.

3. Look at the Specifications:

In case you don’t have a measuring tape at the moment, you can search for the product name in Google and look at the Product Specifications. There is also a good chance of finding the Screen Size on the Product Package Box.

4. How to Measure a Monitor Screen using Formula:

If you are not able to measure diagonally, then look at the vertical and horizontal (length and height) of the monitor. Then use the Mathematical Formulae (Pythagorean theorem) we learned in school.

a² + b² = c²

Example:

If the monitor is 20″ wide (a) and 12″ in length (b). With these, you can calculate the diagonal size (c) of the screen. 

c² = a² + b²

(Screen Size)² = (20.9)² + (12)²

(Screen Size)² = 436.81 + 136.89

Screen Size = √573.7

Screen Size = 23.9

Screen Size = 24 inches (Approx)

With this, you can calculate the Screen Size of a Monitor. However, we recommend using the First Method, as it is easier and time-saving.

Conclusion:

Sometimes a 22″ Screen may not be exactly 22″. You may get 21.8 or 22.2 inches in some cases. However, we consider the Approximate value by ignoring the decimals. So, here are the 4 Methods How to Measure a Monitor Screen on Computer.