How to Measure a TV: Easy Guide for Size & Wall Mounting

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Shopping for a new TV or trying to mount one on your wall? Then it’s important to know exactly how to measure a TV. While most TVs are sold by screen size, that number doesn’t reflect the full dimensions you may need to consider, especially for wall mounting or furniture placement.

This guide explains how to measure a TV correctly, including screen size, overall dimensions, and VESA mount compatibility. Whether you’re working with a smart TV or an older flat screen, measuring it properly ensures the right fit for your room and your viewing needs.

Table of Contents

How to Measure TV Size Diagonally

The most common question people ask is how to measure TV size, and the answer is simple: TVs are measured diagonally.

Here’s how to do it:

  1. Use a tape measure.
  2. Measure from the top left corner of the screen (not the frame) to the bottom right corner.
  3. This gives you the screen size in inches, which is how TVs are marketed (e.g., 55″, 65″).

If you’re wondering: how do you measure the size of a television?, remember this only includes the display area, not the bezels or frame.

How Are Flat Screen TVs Measured?

Many people ask, how are flat screen TVs measured? Like all televisions, they’re measured diagonally across the actual display. This applies whether the screen is LED, OLED, LCD, or QLED.

So, if you’re asking how do I measure a flat screen TV? or how do you measure a flat screen television?, the diagonal method is always correct, screen corner to screen corner, excluding the plastic edge.

How to Measure a TV for a Wall Mount

If you want to mount your TV, knowing how to measure a TV for a wall mount is essential.

Here’s what to measure:

  • Overall width and height: Measure the full frame of the TV, not just the screen, to make sure it fits on your wall.
  • Depth: Some wall mounts need to account for TV thickness.
  • VESA mount pattern: This is the spacing between the four mounting holes on the back.

We cover how to measure VESA mount size later in this post.

How to Measure a TV Display Size

Sometimes you need the display size itself, not the marketed screen size. Here’s how to measure TV display size:

  • Measure only the viewable screen area, from one corner to the opposite diagonal corner.
  • Exclude bezels or borders.

This gives a more accurate idea of what you’ll actually be looking at when watching your TV.

How Do You Measure a Smart TV?

If you’re wondering: how do you measure a smart TV?, the method is exactly the same as for regular TVs. The “smart” part just refers to features like built-in apps or Wi-Fi, it doesn’t affect how you measure it.

Use the diagonal screen measurement and also check dimensions for wall mounting or fitting into furniture.

How Do You Size a TV for a Room?

Not sure what size TV fits best in your space? Here’s how to size a TV for a room:

  1. Measure your viewing distance (in inches).
  2. Divide that number by 1.6 for 4K TVs or 2 for HD TVs.
  3. The result is your ideal TV size in inches.

For example, if you sit 96 inches (8 feet) away from your TV, a 55″–60″ TV is ideal for 4K viewing.

How to Measure a TV VESA Mount Size

If you’re planning to wall mount your TV, knowing how to measure VESA mount size is critical.

Here’s how:

  1. Look at the four mounting holes on the back of the TV.
  2. Measure the horizontal distance between the holes (in millimeters).
  3. Measure the vertical distance between the holes.
  4. Combine the two to get your VESA size (e.g., 400×200).

This tells you what kind of wall mount bracket you’ll need.

How Can I Tell What Size My TV Is?

If you don’t have a manual or box, you may ask, how can I tell what size my TV is?

Here’s how:

  • Use a tape measure.
  • Measure diagonally across the screen (not including bezels).
  • Round to the nearest whole number, that’s your TV size.

You can also check the model number online for official specifications.

FAQ on How to Measure a TV

What does a 55-inch TV actually measure?

A 55-inch TV means the screen measures 55 inches diagonally. The full frame may add 1–2 inches to width and height depending on bezel size.

How are televisions measured when buying online?

Retailers list the diagonal screen size. Check the product description for full TV dimensions, especially if you need it to fit into furniture or a mount.

Do all flat screen TVs use the same measuring system?

Yes, all flat screen TVs are measured diagonally from screen corner to screen corner, regardless of brand or technology (LED, OLED, QLED, etc.).

Why does my TV not seem to match its size?

You may be including the frame in your measurement. TV size refers only to visible screen area, not the bezels.

Can I mount any size TV on any wall?

It depends on the VESA size, wall strength, and available space. Always measure and verify your wall can support the weight and size of your TV.

Final Thoughts on How to Measure a TV

Knowing how to measure a TV properly helps you buy the right size, mount it securely, and make sure it fits your space. Whether you’re sizing a flat screen for a small room or selecting the perfect smart TV for your living room, accurate measurements save time and hassle.

For more tips on measuring electronics and devices, visit our Electronics & Devices category.