The <ratio> CSS data type, used for describing aspect ratios in media queries, denotes the proportion between two unitless values. It is a strictly positive <integer> followed by a slash ('/', Unicode U+002F SOLIDUS) and a second strictly positive <integer>. There may be spaces before and after the solidus.
Examples
| Ratio | Usage | |
|---|---|---|
|  | 4/3 | Traditional TV format in the 20th century. | 
|  | 16/9 | Modern, 'widescreen', TV format. | 
|  | 185/100=91/50(non-integer dividends and divisors are not allowed) | The most common movie format since the 1960s. | 
|  | 239/100(non-integer dividends and divisors are not allowed) | The 'widescreen', anamorphic, movie format. | 
Specifications
| Specification | Status | Comment | 
|---|---|---|
| Media Queries The definition of '<ratio>' in that specification. | Recommendation | Initial definition | 
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) | 
|---|---|---|---|---|---|
| Basic support | (Yes) | 3.5 (1.9.1) | 9 | 9.5 | (Yes) | 
| Feature | Android | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile | 
|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | ? | (Yes) | (Yes) |