What is the Aspect Ratio? (4:3, 16:9, 21:9, CinemaWide)

Updated Jan 27, 2014 By Cedric Demers

The aspect ratio is the proportion between the width and the height of a picture. It is often expressed in the W:H format, where W is the width and H the height. For example, a 16:9 aspect ratio means that for a width of 16 units, the height must be 9 units.

Aspect RatioUsesTVs
4:31.33:1Standard ChannelsOld TVs
16:91.77:1HD ChannelsThe majority of HDTVs
21:92.35:1Most moviesVery few TVs
The most common aspect ratios in the video industry.

Most televisions and computer monitors currently available have an aspect ratio of 16:9, which fits perfectly the high definition television shows. However, movies are usually filmed with a ratio of 21:9, which will results in black bars at the top and bottom of the picture. To fix this, some manufacturers are producing televisions with a 21:9 format (also called Cinemawide). The table shows the most common aspect ratios.

In theaters, this is why the screen widens at the beginning of a movie. Ads shown before the movie have an aspect ratio of 16:9, while the movie itself is 21:9.

What does black bars looks like on different aspect ratio TVs?

Black bars on different aspect ratio
Black bars are filling the extra space when the aspect ratio does not match.

The position and size of black bars on your television depends on two factors: the aspect ratio of your television and the aspect ratio of the video you are watching. Any mismatch between the two will be filled by the black color. This practice is called letterboxing. The following picture shows the black bars for different televisions and aspect ratios (4:3, 16:9 and 21:9). All televisions have the same diagonal length.

If you do not like having black bars, you have two options available in the settings of your TV: cropping or stretching. Cropping the picture is the equivalent of zooming, but it will remove the sides of the picture. Stretching retains all information, but the proportions are not kept.

As you can see, when you watch a 21:9 movie on a normal 16:9 widescreen TV, you will have some black bars at the top and bottom. This is represented by the top center TV in the illustration.

Is a 21:9 TV Worth It?

Comparaison between 21:9 CinemaWide and 16:9 television
A 58" 21:9 TV is equivalent to a 61" for 21:9 media, but only 47" for 16:9 media.

TVs with a 21:9 aspect ratio are rare. A 21:9 TV is only worth it if you watch almost exclusively movies (more than 80% of the time). If you watch a normal 16:9 content (like a HDTV channel) on it, you will see black bars on the sides. This reduces the viewing area for 16:9 content considerably. A 58" 21:9 television correspond to the same viewing area of a 47" for 16:9 content, as you can see in the illustration.

What is CinemaWide?

CinemaWide is the marketing name of Vizio for a television with a 21:9 aspect ratio. CinemaWide is not worth it, unless you watch almost only movies on your television. As shown by the picture above, for a 58", it correspond to a 61" for movies, but 47" for TV shows.

Vizio only released one model with an aspect ratio of 21:9, the 2012 XVT3D CM.


The most common aspect ratio of TVs and monitors is currently 16:9, which also correspond to the aspect ratio of TV Shows. However, movies usually have an aspect ratio of 21:9, which will result in black bars above and below the picture if you watch it on your 16:9 screen.