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How to Measure a TV Screen the Right Way

a tv with a tape measure on the screen in a modern living room

Measuring your TV screen size isn't hard, but there are things to consider before installing it in your room. Learn how to measure a TV screen the right way.

Learning how to measure a TV isn’t difficult, but there are a few issues that you should be aware of.

The most common TV measurement is the screen size, and you can calculate this by measuring diagonally from corner to corner.

However, if you need the TV’s dimensions before installing it in your room, it would be best to determine its width, height, and depth.

You can do this manually by getting a tape measure, or if you know the diagonal size, you can use a calculator to find out the width and height of the screen.

How Do You Measure a TV Screen Size?

man measuring a TV's screen size with a tape measure

Before buying or installing a TV, it can be handy to understand its dimensions. While it isn’t hard to measure a TV, there are a few issues you might want to consider before you get going. Discover which are the best things to measure and why they are important.

Total Time: 5 minutes

1. Measure the TV’s Screen Size

Measuring a TV's diagonal screen size

The TV screen size is measured diagonally between the corners of the visible screen and is usually expressed in inches.

So, if you want to determine the size of your TV screen, you should measure from the top left corner to the bottom right corner. Or from bottom left to top right. It doesn’t matter which because it will be the same.

Don’t include the bezel or frame around the edge of the screen – just the area that will display the picture.

Common TV sizes range from 28 or 30 inches for small LED TVs to 70 or 80 inches or more for large LEDs and OLED screens.

Some manufacturers may describe a TV’s size as a ‘class’ – so they might say it is a 55-inch class. This means that the screen measures 55 inches from corner to corner, including the frame, so the actual visible screen size will be slightly less.

2. Measure the TV’s Width

Measuring the width of a TV screen

If you want to measure the TV to place it in a cabinet or recess, it is best to calculate the exact dimensions.

Therefore, your measurements should include the bezel around the edge of the screen because this will give you a better idea of the exact size of the TV.

Place your ruler on the left edge of the screen and measure across to the right-hand edge. Remember to include the frame on both sides.

You should also consider where the wires for external devices need to go. TVs usually have connections on one edge or the back.

Check your TV to see where the cables connect to your television, and if it’s on one side, make sure you add some extra space there.

You can also use a TV dimensions calculator to determine the width without using a ruler if you know the TV screen size.

3. Find Out the TV’s Height

Measuring the height of a TV screen

To measure the height, place your measure at the top of the frame and find the distance to the frame’s bottom edge.

TVs rarely have connectors at the top or bottom, but if you install the TV on a stand, you should also consider what this will add to the overall height.

If you haven’t purchased the TV yet, the manufacturer’s website will often display the TV’s dimensions, including the stand.

4. Measure the Depth of the TV

Measuring the depth of a TV screen

Before installing a TV, another essential measurement to know is the depth. The depth is the distance from the front of the screen to the back.

Although many modern TVs have extremely thin screens – especially OLED TVs – the back of the TV will always have a thicker section where the TV’s electronics live.

By measuring the TV’s depth, you will know how far the screen will project from the wall or cabinet.

However, you should also check if any of the connections you require are on the back, as this will require more room for installation.

One way to save space at the back is to buy right-angle connectors, making the wires hang down rather than point toward the wall.

Using a TV stand may also add to the overall depth, so don’t forget to check this.


  • No supplies required


  • 1x tape measure or ruler

Projector and TV Screen Dimension Calculator

If you know a TV screen’s diagonal size, you can also work out the screen’s width and height by using a calculator, which will save you from hunting around for a tape measure.

All modern TVs have an aspect ratio of 16:9. So if you know one distance – either diagonal, width or height – it is easy to calculate the others.

For example, you will get the TV screen’s width and height by entering the diagonal screen size. Or, enter the height, and you will get the diagonal and width dimensions.

You can also use this calculator to get your screen dimensions for different aspect ratios. Select 4:3 or 2.39:1 before entering a screen dimension, and you will get the correct lengths.

This can be useful for calculating the size of a projector screen.

If you find this useful, check out the other calculators on this site:

Can You Measure a TV Without a Tape Measure?

You can measure a TV screen without a tape measure, but you will need to do some research.

First, you need to know the diagonal screen size of your television.

You will usually find this written on the back of the TV, often within the model number – look for 55, 65, 75 or similar as part of the model number – this will likely be the diagonal size of your screen in inches.

If not, note the model number and go to the manufacturer’s website, where you can use the model number to find the product page.

The product page should tell you the screen diagonal for your television.

Finally, enter the diagonal distance in the screen dimensions calculator above to get the width and height.

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About The Author

Paul started the Home Cinema Guide to help less-experienced users get the most out of today's audio-visual technology. He has been a sound, lighting and audio-visual engineer for around 20 years. At home, he has spent more time than is probably healthy installing, configuring, testing, de-rigging, fixing, tweaking, re-installing again (and sometimes using) various pieces of hi-fi and home cinema equipment. You can find out more here.

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