How Is Monitor Size Measured? (Answered)

If you walk into any store or check online, one of the first bits of information you are hit with when it comes to a monitor is the size. However, many people might be wondering how the size of a monitor is measured. 

The measurement you see on the box, in store, or online, generally refers to the diagonal length of the measured monitor!

When it comes to your monitor, there are a few methods that can be used to determine the overall size. Depending on whether you want the aspect ratio, diagonal measurement, or surface area for the display, varying methods are available to measure the overall size of your monitor. We will look at some of the most common.

How Is Monitor Size Measured

Depending on which size you are looking to find, there are various methods with which you can measure the correct size you are looking for. We have identified some of the most common sizes you might be looking for when it comes to your monitor:

Surface Area

One of the first sizes you might be looking for is the surface area of the monitor. The surface area directly describes the overall size of the area that you will be viewing. For this, you will need to measure the length of the monitor, followed by the height. A simple height x length calculation should give you the surface area.

Aspect Ratio

The aspect ratio is one of the easiest that you could calculate. Most monitors already have various aspect ratios that you can choose from when viewing. For instance, if the length of 24-inches and the height is 15-inches, the aspect ratio would be 24:15. This would vary depending on the screen and can be made smaller or larger on most monitors.

Diagonal Size

When it comes to measuring the overall size of a monitor, the diagonal size is what most people refer to. You must have heard of people talking about their 40-inch television or monitor right? The indicated size does not refer to the length of the display, but rather the diagonal, which is measured from one corner at the top, to one at the bottom. 

A standard measurement with a ruler should be enough to make this measurement. However, those that want more of a challenge could choose the Pythagorean theorem to measure the diagonal size of the monitor.

Online Checking

If you are unsure about the size of your monitor, you might be able to look it up using the manufacturer’s model number imprinted on the monitor. Almost all products will have a product and batch number located somewhere on the device. This allows you to use the website of the manufacturer to look up all the correct specs.


Since we all want the biggest possible monitor we have room for, it is important to know some of these measurements. You will be surprised to see some of the sizes of the high-end monitors, including curved shapes and unique designs. We would love to see some of your comments on the best sizes for a good monitor and which measuring aspect you find most important.

This article was last updated on September 13, 2022 .

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By Adam

The Display Blog staff account. We know display.