|Some common aspect ratios for displays|
The aspect ratio of a display device is the proportional relationship between its width and its height. It is expressed as two numbers separated by a colon (x:y). Common aspect ratios for displays, past and present, include 5:4, 4:3, 16:10 and 16:9.
As of 2016, most computer monitors use widescreen displays with an aspect ratio of 16:9, although some portable PCs use narrower aspect ratios like 3:2 and 16:10 while some high-end desktop monitors have adopted ultrawide displays.
The following table summarises the different aspect ratios that have been used in computer displays:
|Aspect ratio||Example resolutions||Notes|
|4:3||1024x768, 1600x1200||common until 2003, matches the aspect ratio of analogue TV, non-widescreen SDTV and early 35 mm film|
|5:4||1280x1024||common until 2003|
|3:2||2160x1440, 2560x1700+||used in some portable PCs since 2013|
|16:10||1280x800, 1920x1200||common between 2003 and 2010|
|16:9||1366x768+, 1920x1080||common since 2008, matches the aspect ratio of HDTV and widescreen SDTV|
|~21:9||2560x1080, 3440x1440||used in some professional and gaming displays since 2015, roughly matches various anamorphic formats|
|32:9||3840x1080, 5120x1440||used in some high-end displays since 2017|
+ The resolution doesn't match the aspect ratio exactly, but is commonly marketed or described as such.
Until about 2003, most computer monitors had a 4:3 aspect ratio and some had 5:4. Between 2003 and 2006, monitors with 16:10 aspect ratio became commonly available, first in laptops and later also in standalone computer monitors. Reasons for this transition was productive uses for such monitors, i.e. besides widescreen movie viewing and computer game play, are the word processor display of two standard letter pages side by side, as well as CAD displays of large-size drawings and CAD application menus at the same time. 16:10 became the most common sold aspect ratio for widescreen computer monitors until 2008.
In 2008, the computer industry started to move from 4:3 and 16:10 to 16:9 as the standard aspect ratio for monitors and laptops. A 2008 report by DisplaySearch cited a number of reasons for this shift, including the ability for PC and monitor manufacturers to expand their product ranges by offering products with wider screens and higher resolutions, helping consumers to more easily adopt such products and "stimulating the growth of the notebook PC and LCD monitor market".
By 2010, virtually all computer monitor and laptop manufacturers had also moved to the 16:9 aspect ratio, and the availability of 16:10 aspect ratio in mass market had become very limited. In 2011, non-widescreen displays with 4:3 aspect ratios still were being manufactured, but in small quantities. The reasons for this according to Bennie Budler, product manager of IT products at Samsung South Africa was that the "demand for the old 'Square monitors' has decreased rapidly over the last couple of years". He also predicted that "by the end of 2011, production on all 4:3 or similar panels will be halted due to a lack of demand."
3:2 displays first appeared in computers in 2013 with the Chromebook Pixel and later gained popularity in 2-in-1 PCs like Microsoft's Surface line. As of 2018, a number of manufacturers are either producing or planning to produce portable PCs with 3:2 displays.
Since 2014, a number of high-end desktop monitors have been released that use ultrawide displays with aspect ratios that roughly match the various anamorphic formats used in film, but are commonly marketed as 21:9. Resolutions for such displays include 2560x1080, 3440x1440 and 3840x1600.
From 2005 to 2013 most video games were mainly made for the 16:9 aspect ratio and 16:9 computer displays therefore offer the best compatibility. 16:9 video games are letterboxed on a 16:10 or 4:3 display or have reduced field of view.
4:3 monitors have the best compatibility with older games released prior to 2005 when that aspect ratio was the mainstream standard for computer displays.
As of 2017, the most common aspect ratio for TV broadcasts is 16:9, whereas movies are generally made in the wider 21:9 aspect ratio. Most modern TVs are 16:9, which causes letterboxing when viewing 21:9 content, and pillarboxing when viewing 4:3 content such as older films or TV broadcasts, unless the content is cropped or stretched to fill the entire display.
Microsoft recommends a 16:9 display for Office 2013.
For viewing documents in A4 paper size (which has a 1.41:1 aspect ratio), whether in portrait mode or two side-by-side in landscape mode, 4:3 or 16:10 fits best. For photographs in the standard 135 film and print size (with a 3:2 aspect ratio), 16:10 fits best; for photographs taken with consumer-level digital cameras, 4:3 fits perfectly.
The size of a computer monitor is given as the diagonal measurement of its display area, usually in inches. Wider aspect ratios result in smaller overall area, given the same diagonal.
|DAR||Image dimensions||Display area||Image area 4:3 content||Image area 16:9 content||Image area 2.35:1 content|
|4:3||18.4 in × 13.8 in (47 cm × 35 cm)||254.0 sq in (1,639 cm2)||254.0 sq in (1,639 cm2)||189.9 sq in (1,225 cm2)||143.7 sq in (927 cm2)|
|16:10||19.5 in × 12.2 in (50 cm × 31 cm)||237.7 sq in (1,534 cm2)||197.6 sq in (1,275 cm2)||213.7 sq in (1,379 cm2)||161.6 sq in (1,043 cm2)|
|16:9||20.1 in × 11.3 in (51 cm × 29 cm)||226.0 sq in (1,458 cm2)||168.9 sq in (1,090 cm2)||226.0 sq in (1,458 cm2)||171.2 sq in (1,105 cm2)|
Until 2010, smartphones used different aspect ratios, including 3:2 and 5:3. Since then, most smartphone manufacturers have switched to using 16:9 widescreen displays, driven at least partly by the growing popularity of HD video using the same aspect ratio.
Since 2017, a number of smartphones have been released using 18:9 or even wider aspect ratios (such as 18.5:9 or 19.5:9); such displays are expected to appear on increasingly more phones. Reasons for this trend include the ability for manufacturers to use a nominally larger display without increasing the width of the phone, as well as the 18:9 ratio being well-suited for VR applications and the proposed Univisium film format.
Most televisions were built with an aspect ratio of 4:3 until the early 2010s, when widescreen TVs with 16:9 displays became the standard. This aspect ratio was chosen as the geometric mean between 4:3 and 2.35:1, an average of the various aspect ratios used in film. While 16:9 is well-suited for modern HDTV broadcasts, older 4:3 video has to be either padded with bars on both sides, cropped or stretched, while movies shot with wider aspect ratios are usually letterboxed, with black bars on top and bottom.