About this tool
A screen size calculator turns the diagonal number on a box, such as 27 inches, into the width and height you can measure with a ruler.
Screens are sold by diagonal length, but whether a monitor fits your desk depends on its width and height.
The tool uses width = diagonal x ratio width / sqrt(ratio width squared + ratio height squared), and the same for height, then multiplies by 2.54 to get centimeters.
For example, a 27 inch 16:9 monitor is about 59.8 cm wide and 33.6 cm tall, while a 55 inch 16:9 TV is about 121.8 cm wide and 68.5 cm tall. Why is a 27 inch ultrawide narrower in height than a 27 inch 16:9?
Because the same diagonal stretched to 21:9 gives a wider and shorter panel, so change the ratio fields to compare. Which ratio should I enter?
Check the spec sheet: 16:9 is common for TVs and monitors, 16:10 for many laptops, 21:9 for ultrawide.
The result is the visible panel only; the bezel, stand and any curve are not included, so leave a few extra centimeters on the desk or TV stand.
For other length conversions, use the length converter or the unit converter. Results are for reference; sizes printed on products are rounded.
How to use
- Enter the diagonal size in inches from the product label.
- Enter the aspect ratio, such as 16 and 9 (see the spec sheet).
- Read the width and height in cm and inches, then compare with your desk or TV stand.