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<ratio>

The <ratio> CSS data type, used for describing aspect ratios in media queries, denotes the proportion between two unitless values.

Syntax

The <ratio> data type consists of a strictly positive <integer> followed by a forward slash ('/', Unicode U+002F SOLIDUS) and a second strictly positive <integer>. Spaces before and after the slash are optional. The first number represents the width, while the second represents the height.

Examples

Use in a media query

@media screen and (min-aspect-ratio: 16/9) { ... }

Common aspect ratios

Ratio Usage
Ratio4_3.png 4/3 Traditional TV format in the 20th century.
Ratio16_9.png 16/9 Modern "widescreen" TV format.
Ratio1_1.85.png 185/100 = 91/50
(non-integer dividends and divisors are not allowed) 		The most common movie format since the 1960s.
Ratio1_2.39.png 239/100
(non-integer dividends and divisors are not allowed) 		"Widescreen," anamorphic movie format.

Specifications

Specification Status Comment
Media Queries
The definition of '<ratio>' in that specification.		 Recommendation Initial definition.

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
Basic support Yes Yes 3.5 9 9.5 Yes
Mobile
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support Yes Yes Yes Yes Yes Yes Yes

See also

Edit this page on MDN

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https://developer.mozilla.org/en-US/docs/Web/CSS/ratio