TV 55 inches in centimeters will have a diagonal of 139.7. How did you get this number? An inch is equal to 2.54 centimeters, to convert to inches you need: 2.54 * 55 = 139.7. Because one inch is 2.54 times a centimeter.

The calculations do not end there, because in many cases you also need to know the length and height of the screen, and it depends on the format.

**They meet with the ratios:**- 16: 9 – most common in TVs, monitors
- 16:10 – screens of laptops, widescreen monitors
- 21: 9 – Rarer ultra-widescreen TVs

The ratio means that the length is 16 parts, and the height is 10, in the case of a 16:10 format. This abstract meaning is simply an indication of proportions. In other words, the length is 1.6 times greater than the height.

There are other aspect ratios, but they mostly apply to older monitors and other specialized video systems.

In any case, the calculation method will be given here, not just the data. So that you can always be fully armed and calculate what you need. Let’s get started!

## How do I calculate height and length of a 55 inch TV?

**Take the popular 16: 9 for example.**

- The first step is to square both numbers and add: 16 * 16 + 9 * 9 = 337
- Now get the root (a calculator is useful here) of 337 = 18.35
- Here we find an unknown number x, which will translate the ratio into centimeters, for this: 139.7 / 18.35 = 7.61 (the diagonal in centimeters was divided by the resulting root in point 2)
- The found unknown X = 7.61 will translate the abstract 16: 9 into centimeters
- We get the values:
- screen length 16 * 7.61 = 121.76 cm
- screen height 9 * 7.61 = 68.49 cm

To find the length and height, you definitely need to know the aspect ratio and the diagonal, this is a minimum of data. Everything is based on the laws of geometry and mathematics, it is important to remember only the order of actions. Here it is simple, if it is not clear, then you should carefully go through the points again.

Having made a similar calculation, substituting your data, you can always find out how many centimeters the height and height of any screen is.

*What if the other way around? We have length and height data, but we don’t know the diagonal. Everything is simple here.*

Here is a complete comparison guide on HDMI Arc Vs EArc.

### How to find the diagonal in length and height?

Square the length, then the height, sum them up and get the root of the sum.

**Example:** Let’s check the above calculations and find the value for a TV with a length of 121.76 cm and a height of 68.49 cm.

- So you need:
- Length squared 121.76 * 121.76 = 14825
- Height squared 68.49 * 68.49 = 4691
- Their sum is 19516 = 139.7 root of the sum
- Diagonal 139.7 cm

In the event that you need to know the dimensions with frames around the TV screen, you can add a few centimeters to the sides. But here, as you know, it strongly depends on the design of the model and you cannot do without accurate measurement.

All the basic calculations that are often required have been performed and shown here. Not only examples are shown, but also formulas are given, an understanding of how it turns out. If the data is of increased importance, then play it safe and double-check in other sources. Since no one is immune from mistakes, no matter how hard he tries to avoid them.