Aspect ratio

The aspect ratio of a geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height,^[1]^[2] when the rectangle is oriented as a "landscape".

For other uses, see Aspect ratio (disambiguation).

The aspect ratio is most often expressed as two integer numbers separated by a colon (x:y), less commonly as a simple or decimal fraction. The values x and y do not represent actual widths and heights but, rather, the proportion between width and height. As an example, 8:5, 16:10, 1.6:1, 8⁄5 and 1.6 are all ways of representing the same aspect ratio.

In objects of more than two dimensions, such as hyperrectangles, the aspect ratio can still be defined as the ratio of the longest side to the shortest side.

Image aspect ratio

High Aspect Ratios allow the construction of tall microstructures without slant

HARMST

Tire code

Tire sizing

impeller sizing

Turbocharger

of an aircraft or bird

Wing aspect ratio

of an optical lens

Astigmatism

Nanorod dimensions

Shape factor (image analysis and microscopy)

Finite Element Analysis

The term is most commonly used with reference to:

4:3 = 1.3: Some (not all) 20th century computer monitors (, XGA, etc.), standard-definition television

VGA

${\sqrt {2}}:1=1.414...$ : international paper sizes ()

ISO 216

3:2 = 1.5: , iPhone (until iPhone 5) displays

35mm still camera film

= 1.6: commonly used widescreen computer displays (WXGA)

16:10

Φ:1 = 1.618...: , close to 16:10

golden ratio

5:3 = 1.6: , a standard film gauge in many European countries

super 16 mm

16:9 = 1.7: TV and most laptops

widescreen

2:1 = 2:

dominoes

64:27 = 2.370: ultra-widescreen,

21:9

32:9 = 3.5: super ultra-widescreen

The diameter-width aspect ratio (DWAR) of a compact set is the ratio of its diameter to its width. A circle has the minimal DWAR which is 1. A square has a DWAR of ${\sqrt {2}}$ .

The cube-volume aspect ratio (CVAR) of a compact set is the d-th root of the ratio of the d-volume of the smallest enclosing axes-parallel d-cube, to the set's own d-volume. A square has the minimal CVAR which is 1. A circle has a CVAR of ${\sqrt {2}}$ . An axis-parallel rectangle of width W and height H, where W>H, has a CVAR of ${\sqrt {W^{2}/WH}}={\sqrt {W/H}}$ .

In geometry, there are several alternative definitions to aspect ratios of general compact sets in a d-dimensional space:^[3]

If the dimension d is fixed, then all reasonable definitions of aspect ratio are equivalent to within constant factors.

Notations[edit]

Aspect ratios are mathematically expressed as x:y (pronounced "x-to-y").

Cinematographic aspect ratios are usually denoted as a (rounded) decimal multiple of width vs unit height, while photographic and videographic aspect ratios are usually defined and denoted by whole number ratios of width to height. In digital images there is a subtle distinction between the display aspect ratio (the image as displayed) and the storage aspect ratio (the ratio of pixel dimensions); see Distinctions.