What is the aspect ratio of 1920 by 1080?

1920 x 1080 can be reduced to 16:9. Both numbers are divisible by 120 and when divided they give 16 and 9. This is the standard widescreen format used for HDTV and most online videos.

How do I resize an image without distorting it?

Don't change the aspect ratio. Enter the original width and height, enter the desired new width, and leave the new height field blank. A calculation tool will adjust the height accordingly to keep the image's original shape.

What is the difference between aspect ratio and resolution?

Aspect ratio is represented by values like 16:9 and indicates the shape, while resolution is indicated by values such as 1920x1080 and describes the actual size of pixels. The same aspect ratio can have different resolutions. An image with a size of 640 x 360 and an image with a size of 3840 x 2160 both can have an aspect ratio of 16:9.

What aspect ratio should I use?

For widescreen videos and most displays it's 16:9, for smartphone videos and short content it's 9:16, for square social media posts it's 1:1, for retro content and presentations it's 4:3, and for ultrawide displays and cinema screens it's 21:9.

How to calculate width and height from screen's diagonal size?

A calculation tool converts the diagonal size to width and height based on aspect ratio. If you enable the option for physical screen size and enter the diagonal size, then it will give you actual width and height in inches or centimeters.

Aspect Ratio Calculator

Dimensions

Original width (px)

Original height (px)

New width (px)

New height (px)

Enter a width and height to read off the aspect ratio. To resize, add a third value and leave the one you want blank.

Round results to whole pixels

Pixel dimensions must be whole numbers, so the solved value is rounded.

Work out the physical screen size

Enter a diagonal to get the real width and height at this aspect ratio.

Please input values into the fields

The aspect ratio calculator will calculate the width to height ratio of images, videos or screens and prevent distortion when resizing. Enter the width and height to check the aspect ratio (e.g. 16:9). To resize enter three out of four fields leaving the one you want calculated blank.

What is an aspect ratio?

Aspect ratio describes the rectangular shape of something - how wide it is compared to how tall it is. It's expressed as two numbers separated by a colon, like 16:9 or 4:3. The first number represents the width and the second number represents the height.

The aspect ratio determines the shape of an image, not its size. An image that is 1920 x 1080 pixels and a thumbnail that's 320 x 180 pixels can both have an aspect ratio of 16:9. When you change one dimension, you must also change the other in proportion to maintain the same shape. Otherwise, your image will look distorted or stretched.

How to use this calculator:

Enter the original width and height in the first two fields to display the simplified ratio and ratio as a decimal. To maintain size, enter a new width and leave the field for new height blank or vice versa. The calculator will automatically fill in the missing values.

If you enable the Round to pixel value option, then you will get integer results. This is because there are no half pixels on a screen. If you enable the Physical Screen Length option and enter a diagonal size, then it calculates the actual width and height of the display in inches or centimeters.

Calculation equation:

All size combinations with the same aspect ratio follow the same width to height ratio.

\frac{W_1}{H_1} = \frac{W_2}{H_2}

By rearranging this ratio you can find missing values. For example, if you want to calculate a new height from a new width then the following is true:

H_2 = \frac{H_1 \times W_2}{W_1}

Assuming the size of a photo is 1600 by 1200 pixels and you want a new width of 400 pixels, then the new height will be calculated by dividing the original height by the original width and multiplying it with the new width.

H_2 = \frac{1200 \times 400}{1600} = 300

To express two quantities in a simple ratio, divide each quantity by their greatest common divisor. For 1920 x 1080 the greatest common divisor is 120. So the ratio is found by dividing 1920 by 120 and dividing 1080 by 120, giving a result of 16:9.

Typical image ratios

Many content uses some standard formats. The following table summarizes the most common aspect ratios, their corresponding decimal values, and typical use cases for each ratio.

Ratio	Decimal	Where it is used
1:1	1.00	Square social posts, avatars, app icons
4:3	1.33	Older TVs and monitors, many tablets
3:2	1.50	DSLR photography, 35mm film
16:10	1.60	Some laptops and monitors
16:9	1.78	HDTV, YouTube, most modern screens
21:9	2.33	Ultrawide monitors, cinema
9:16	0.56	Phone video, TikTok, Reels, Shorts

Calculate physical screen size

Screens are often sold by their diagonal measurement but it is also common to know the width and height. When both the diagonal and aspect ratio are known, then the actual width can be calculated by multiplying the diagonal by the width factor of the ratio and dividing that result by the diagonal of the ratio itself.

W = \frac{D \times a}{\sqrt{a^2 + b^2}} \qquad H = \frac{D \times b}{\sqrt{a^2 + b^2}}

For a 16:9 display with a size of 27 inches the calculated width is about 23.5 inches and height is about 13.2 inches. When "Physical screen size" option is enabled, you can calculate the width for any diagonal.

Cutting and borders

When you place content into a frame with different aspect ratio, you always have to choose one of the options. Cropping will cut off borders to fill in the new screen and is best for images where the central content is most important. Padding adds border around the content so that no content is lost and is good for images which should not be cropped. Neither method changes the aspect ratio itself, only how the original shape fits into a new one.

Frequently asked questions

What is the aspect ratio of 1920 by 1080?: 1920 x 1080 can be reduced to 16:9. Both numbers are divisible by 120 and when divided they give 16 and 9. This is the standard widescreen format used for HDTV and most online videos.
How do I resize an image without distorting it?: Don't change the aspect ratio. Enter the original width and height, enter the desired new width, and leave the new height field blank. A calculation tool will adjust the height accordingly to keep the image's original shape.
What is the difference between aspect ratio and resolution?: Aspect ratio is represented by values like 16:9 and indicates the shape, while resolution is indicated by values such as 1920x1080 and describes the actual size of pixels. The same aspect ratio can have different resolutions. An image with a size of 640 x 360 and an image with a size of 3840 x 2160 both can have an aspect ratio of 16:9.
What aspect ratio should I use?: For widescreen videos and most displays it's 16:9, for smartphone videos and short content it's 9:16, for square social media posts it's 1:1, for retro content and presentations it's 4:3, and for ultrawide displays and cinema screens it's 21:9.
How to calculate width and height from screen's diagonal size?: A calculation tool converts the diagonal size to width and height based on aspect ratio. If you enable the option for physical screen size and enter the diagonal size, then it will give you actual width and height in inches or centimeters.

Related calculators

Audio File Size CalculatorEstimate the size of an audio file from its length and quality, for both compressed formats like MP3 and uncompressed formats like WAV, in decimal and binary units.

Two's Complement CalculatorConvert a decimal number to two's complement binary and back, with a step-by-step invert-and-add-one breakdown, the hex form, the sign bit, and the value range for 4-, 8-, 12-, and 16-bit widths.

Bandwidth CalculatorConvert between data units, estimate download and upload time, size a website's bandwidth, and turn a monthly data cap into a sustained speed.

Bytes to GB CalculatorConvert bytes to gigabytes and every other data unit, with the decimal (GB) and binary (GiB) values shown side by side.

Bitwise CalculatorPerform bitwise operations on two decimal numbers - AND, OR, XOR, NAND, NOR, XNOR, NOT and shifts - with a bit-by-bit breakdown, a truth table, set-bit count and results in binary, octal, decimal and hex across 4, 8, 16 and 32-bit registers.

Amdahl's Law CalculatorCompute parallel speedup with Amdahl's Law from the parallel fraction and processor count. See the efficiency, the maximum-speedup ceiling, a runtime estimate, and a Gustafson comparison, or solve backward for the parallel fraction.

Disclaimer: This calculator is provided for general informational and educational purposes only. Our calculators are under active development, and results may be inaccurate, incomplete, or unsuitable for your situation. Always verify the figures independently and seek advice from a qualified professional before relying on them. We make no warranties and accept no liability for any loss or decision arising from use of this tool.

References

Wikipedia: Aspect ratio (image)
Definition, notation, and common image and video aspect ratios.
Wikipedia: 16:9 aspect ratio
History and standardisation of the widescreen 16:9 format.
Wikipedia: Greatest common divisor
The method used to reduce a width and height to a simplest ratio.