aspect ratio (redirected from aspect ratios)

The ratio of width to height of an object. Stating the relationship of one side to the other, it is widely used to describe the shape of a TV or computer screen. For example, the aspect ratio of a standard screen is 4:3, which is a relatively square rectangle. The 4:3 means "4 to 3," or four units wide to three units high. High-definition TV (HDTV) has a 16:9 ratio, which is a wide rectangle closer in width, but still not as wide, as most cinema screens.

Another way of expressing the 4:3 and 16:9 ratios is 1.33:1 and 1.78:1, but these latter designations are used mostly for cinema formats, not TV (see below).

Standard or Wide Screen?
The common measurement of a computer monitor or TV is the screen's diagonal measurement in inches. However, a 20" screen does not disclose whether its layout is 4:3 (square) or 16:9 (wide). See letterbox, HDTV display modes and anamorphic DVD.

Standard and HDTV Aspect Ratios

Fitting the wide screen HDTV image (16:9) on the right into a standard TV (4:3) on the left creates the "letterbox effect" (black bars on top and bottom). (Image courtesy of Intergraph Computer Systems.)

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(graphics)

aspect ratio - The ratio of width to height of a pixel, image, or display screen. Square pixels (1:1) are considered preferable but displays are usually about 5:4.