Aspect ratio (image)
The aspect ratio of an image is its width divided by its height. Aspect ratios are mathematically expressed as x :y (pronounced “x-to-y”) and x×y (pronounced “x-by-y”). The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1[1]. Two common videographic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently. In still camera photography, the most common aspect ratios are 4:3 and 3:2, though other aspect ratios, such as 5:4, 6:7, and 1:1 (square format), are used.