Video Aspect Ratio Calculator

Calculate the aspect ratio for a video display resolution by entering the resolution in A and B to find the video aspect ratio.

Scale a resolution or compare if 2 resolutions are the same aspect ratio by entering the desired width and height in box C or D.

Enter an Aspect Ratio:
Aspect Ratio One
:
=
Aspect Ratio Two
:

Aspect Ratio:



How to Calculate an Aspect Ratio

An aspect ratio indicates the shape of a video screen or display. Screens display images as a grid of colored squares or rectangles in a grid and the width and height of that grid is the resolution. The aspect ratio is the ratio of the number of columns to the number of rows of pixels that make up a display.

An aspect ratio is often expressed as reduced to a common format based on industry standards. To find the video aspect ratio reduce the aspect ratio to either 16:9, 16:10, or 4:3. Some video aspect ratios cannot be evenly reduced into these ratios, in which case they should be reduced to the number of columns to 1 row of pixels.

To reduce a ratio, find the greatest common factor of both the number of columns and the number of rows. Then divide the number of rows and the number of columns by the greatest common factor.

Example: let’s find the aspect ratio for a 3840×2160 resolution display.

The greatest common factor of both 3840 and 2160 is 240

num columns = 3840 ÷ 240 = 16
num rows = 2160 ÷ 240 = 9
aspect ratio = 16:9

Common Aspect Ratios Used in Video Applications

There are many aspect ratios used for various purposes in film and video, and some are more common than others. The most common is 16:9, see the table below for the most common ratios for each type of use.

Common aspect ratios for different video uses
Video Format Common Aspect Ratios
Cinema 1.85:1, 2.39:1
TV Video 4:3, 16:9
Computers 4:3, 16:10

See more common aspect ratios and resolutions.

The most common video aspect ratios for TV and video are 4:3, 16:9, and 2.39:1

Displaying Video in a Different Aspect Ratio

Sometimes video in one aspect ratio needs to be displayed on a screen that is a different resolution, for example when displaying standard definition 4:3 TV on a high definition 16:9 display.

There are a few different ways to display video that is not the same aspect ratio as the screen.

Display a Different Aspect Ratio by Cropping

The video can be be zoomed so that there is no extra space, which will crop part of the video.

For example, a 4:3 video can be zoomed so that the width is equal to the width of the 16:9 screen, cropping the top and bottom of the video.

Zooming and cropping video to display a 4:3 video on a 16:9 screen
Cropping the video results in losing the top and bottom of the image

Display a Different Aspect Ratio by Pillar-boxing

The video can be pillar-boxed, which is keeping the height of the video the same as the display when the video aspect ratio is thinner than the display aspect ratio. For example, a 4:3 video can be zoomed so that the height of the video is the same as the height of the display, resulting in bars on either side of the video.

Using a pillar box to display a 4:3 video on a 16:9 screen
Pillar-boxing the video results in black bars on the left and right of the image

Display a Different Aspect Ratio by Letterboxing

The video can be letter boxed, which is keeping the width of the video the same as the display when the video aspect ratio is wider than the display aspect ratio. For example, a 16:9 video can be zoomed so that the width of the video is the same as the width of the display, resulting in bars on top and bottom of the video.

Using a letterbox effect to display a 16:9 video on a  4:3 screen
Letterboxing the video results in black bars on the top and bottom of the image

You might be interested our TV viewing distance calculator to calculate the resolution and size of TV you should get based on your seating distance.