How Wide Is a 40 Inch TV?

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Updated February 10, 2023

Users and manufacturers measure the size of the screen diagonally when creating the best TVs on the market. This measure goes from one upper corner to the lower corner on the opposite side.

To understand how wide a 40-inch TV is, you could calculate the width and height using algebra or trigonometry. However, the size you get will be slightly less wide than the TV because it does not include the edge, called the bezel.

The most important factor when considering screen size is the viewing distance. Generally, you will want to be twice as far away from a 40-inch screen as you would for a 32-inch one for optimal viewing experience. As such, if you have limited space and cannot sit very far away from your screen, it might be better to opt for a smaller screen. On the other hand, if you have enough space and desire an immersive viewing experience, a larger screen would be ideal. Ultimately, it is important to consider screen size in relation to your viewing distance before making a purchase.

If you are in the market for a 40-inch TV, you can check out the TCL 40S325 for a quality smart TV.


  • A 40” TV is 40 in. across the diagonal of the screen.
  • The width of a 40” screen using the 16:9 aspect ratio is about 34.9” wide, but this does not include the bezel.
  • The width of the bezel varies between different models.

How Are TV Screens Measured?

Person watching 40-inch wide TV in living room

The size of the TV listed in a product’s title is the screen measured diagonally from one corner to the other. So, a 40” TV is 40” across the diagonal and does not include the bezel surrounding the screen. This is important to remember when considering immersive experiences and common sizes. A 40” TV can look very different from an actual size of 40” as the bezel will add extra inches. To ensure you get the immersive experience you desire, make sure to account for the bezel in any calculation of a television’s actual size.

If you are interested, you can compare the differences in our comparison of 39-inch TV vs 40-inch. You can also find out how wide a 55-inch tv is if you want a larger TV screen.

Additionally, if the word “class” appears after the size, the screen is not precisely the size shown. Usually, the difference is less than half an inch.

To calculate the height and width of a TV, you could use algebra. For example, you know the aspect ratio is 16:9 (16/9), and the diagonal is 40 inches. Then, you could use the Pythagorean theory to calculate what one unit is in inches and then multiply that by 16 for the width and then 9 for the height. However, you can also find a website that will calculate for you. These websites are pretty widespread when you do a web search for them. Finally, most product descriptions contain the product’s dimensions. For example, one of the Samsung 40-inch 1080p LED HDTVs measures, without the stand, 3.7 inches deep by 36.1 inches wide by 21 inches high, according to Sears.

How Do You Choose the 40-Inch TV That Is Best for You?

Your desired features depend on what you want to watch and which features are important to you. For example, if you know your TV will frequently be used for larger viewing parties, you’ll want a TV with wider viewing angles, allowing all your guests to see similar images from different areas of the room. Your budget may also factor into the ideal TV. Some features may make the TV more expensive, but they may still be less expensive than larger TVs. In that case, if you want to save on features, you can learn how to connect an external hard drive to a TV for instant movies.

40 inch wide TV viewing distance in white and grey living room space

Alternatively, if you want to have some movie nights outside, consider getting an outdoor TV that’s been tested to handle the outdoors well.

You may find 40” TVs with higher resolutions, such as 4K resolution, and image-enhancing features, like HDR. 4K resolution refers to the resolution of a TV with roughly 4,000 pixels along the horizontal axis. These TVs contain significantly more than 4,000 pixels since the pixels sit in a grid shape. For an affordable 4K option, you can check out our TCL 40S325 review. HDR refers to a high dynamic range, which increases the contrast between colors. As a result, HDR TVs present brighter, more vivid images. Don’t know if your TV supports HDR. You can simply find out how to tell if your TV has HDR.

STAT: The Samsung 40-inch 1080p LED HDTV measures, without the stand, 3.7 inches deep by 36.1 inches wide by 21 inches high, according to Sears. (source)

Ideal Viewing Distance for TV

TVs often have an ideal viewing distance because viewing from that distance shows the screen as it was intended to be viewed. Additionally, sitting too close can affect your eyes in different ways, including eye strain. The recommended distance for a 4K TV is 1.5 times the vertical screen size, while the ideal length for HDTV is three times. So, for a 40” TV with 4K, the distance is just under 2.5 feet. For a 40-inch TV with HD, the space between you and the TV is about 4.92 feet. You most likely do not need to measure the distance because an approximation should work fine. If you don’t mind a non-4k TV, you can check out our Sansui 40 Inch 1080P FHD DLED TV review for a budget option to see if it will suit your needs. Additionally, if you are going to mount the TV on the wall, you should read about how high the TV should be mounted.


How do you calculate the height and width of a TV?

You could use the method listed above or one of the websites that do the calculations for you.

Is a 40-inch TV big enough?

A 40” TV is considered to be medium-sized. However, these TVs are perfect for rooms that are not big enough to house a larger model.

How many centimeters are 40 inches?

Forty inches is 101.6 cm. For TVs, remember this is the distance across the diagonal of the screen and does not include the bezel.

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