Aspect ratio (image)

The aspect ratio of an image describes the proportional relationship between its width and its height. It is commonly expressed as two numbers separated by a colon, as in 16:9. For an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this same length unit, the height will be measured to be y units.

In, for example, a group of images that all have an aspect ratio of 16:9, one image might be 16 inches wide and 9 inches high, another 16 centimeters wide and 9 centimeters high, and a third might be 8 yards wide and 4.5 yards high.

Some common examples

The most common aspect ratios used today in the presentation of films in cinemas are 1.85:1 and 2.39:1. Two common videographic aspect ratios are 4:3 (1.33:1), the universal video format of the 20th century, and 16:9 (1.77:1), universal for high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently.