Aspect Ratio

What it's for

Work out the shape of a screen, picture or video: the aspect ratio of a width and height, the nearest common ratio, or the missing side when you know the ratio and one side. A table shows the same shape at common widths.

For example, when a design is 1366 by 768 and you want to know whether it is really 16:9, or you need the height of a 16:9 video that is 1000 pixels wide.

How to use it

Type a Width and a Height to see their ratio, reduced as far as it goes (1920 × 1080 is 16:9), the ratio as a decimal and the nearest common ratio, with how far off it is when the match isn’t exact.

To find a side, leave one of the two boxes empty and write a Ratio such as 16:9, 4/3 or 1.78. The missing side is rounded to a whole number. Either way, a table lists the height for common widths from 320 to 7680 pixels. Copy a link to this input keeps the numbers and ratio.

Example

Choose Try an example, or type a width of 1366 and a height of 768. The ratio is 683:384, and the nearest common ratio is 16:9, 0.05% off.

Good to know

Sizes with decimals are read to four decimal places of ratio. The nearest common ratio comes from a short list (1:1, 5:4, 4:3, 3:2, 16:10, 16:9, 2:1, 21:9 and 32:9, and the same turned upright), so unusual shapes may not be close to any. Heights in the table are rounded to whole pixels, so they can be a pixel off the exact ratio.