What does aspect ratio stand for on a monitor?

What does aspect ratio stand for on a monitor?


What does aspect ratio stand for on a monitor?

Introduction to Aspect Ratios

The aspect ratio of a portable monitor refers to the proportional relationship between its width and height, typically expressed as two numbers separated by a colon. For example, 16:9 indicates the monitor is 16 units wide for every 9 units in height.

Some common aspect ratios used today include:

  • 4:3 - The traditional aspect ratio used for early television sets. It provides a more square-shaped display.
  • 16:9- This widescreen aspect ratio is the standard for HDTVs and computer displays today. It provides a more rectangular, cinematic view.
  • 16:10- A compromise between 4:3 and 16:9, common for computer displays. It offers more vertical space than 16:9.

The concept of aspect ratio originated in the late 19th century with Thomas Edison's invention of the kinetoscope, an early motion picture device. The first kinetoscope films were 1.33:1 or 4:3 aspect ratio, matching the size of the film reels used.

Over the decades, advances in technology and shifts in the film/TV industry led to changes in standard aspect ratios, from the early cinema standard of 4:3 to the HDTV widescreen of 16:9. Computer displays also transitioned from 4:3 to 16:10 and 16:9 with high-resolution digital formats.


4:3 Aspect Ratio

The 4:3 aspect ratio refers to a device width of 4 units and height of 3 units. As mentioned above, this ratio was popularized in the late 19th century by Thomas Edison with his motion picture exhibition device.

From the early 20th century up until the early 2000s, 4:3 remained the standard aspect ratio for television sets, which was carried over from cinema standards at the early cinema era. The ratio provided a good balance between the vertical and horizontal space needed for common types of content, it allowed for efficient and high quality transmission and display.

During the rise of high definition television and portable monitor, 16:9 gradually replaced 4:3 as the most common aspect ratio. However, 4:3 is still sometimes used for standard definition broadcasts and displays. Overall, the 4:3 aspect ratio has had a long history and served as the primary standard for many decades of film and television content.


16:9 Aspect Ratio

The 16:9 aspect ratio emerged as a standard with the introduction of high-definition television (HDTV) in the 1990s. While not as squarish as the older 4:3 standard, the 16:9 aspect ratio provided a wider horizontal view that fits human visual perception, well-suited widescreen movies and modern television programming. Most laptops and portable monitors now use 16:9.

Today, 16:9 is the mainstream and most prevalent aspect ratio for video production and display. Most movies, television shows, YouTube videos, smartphones and consumer cameras now capture video in the 16:9 widescreen aspect ratio as the default. Both 1080p and 4K resolutions use the 16:9 screen dimensions. For consumers, 16:9 is the aspect ratio they are most familiar with when viewing content on modern televisions, streaming devices and mobile devices. Overall, 16:9 strikes a good balance for general use.


16:10 Aspect Ratio

16:10 offers a taller aspect ratio compared to 16:9, providing more vertical space that is well-suited for productivity tasks on monitors. The extra vertical space allows more content to be displayed on monitor at once, reducing excessive scrolling while working on documents, spreadsheets, webpages, and other programs.

Many professionals prefer 16:10 monitors over 16:9 monitors for several key reasons:

  • More vertical space to view more content.
  • Reduced need for scrolling, increasing productivity.
  • Displays more menu options simultaneously.
  • Wider field of view in first-person video games.
  • Less black bar letterboxing needed for films.

When choosing an aspect ratio, consider the type of content you'll primarily view and the monitor shape you prefer. 16:9 is versatile for both productivity and entertainment. 16:10 is good if you value vertical space. 


Calculating Aspect Ratios

You can easily calculate the aspect ratio of a display by dividing its width resolution by its height resolution. For example, a 1920 x 1080 resolution would have an aspect ratio of 1920/1080 = 1.78, which rounds to 16:9.

Some common aspect ratio calculations:

  • 1920 x 1440 resolution: 1920/1440 = 1.33, rounding to 4:3
  • 1920 x 1200 resolution: 1920/1200 = 1.6, rounding to 16:10
  • 1280 x 720 resolution: 1280/720 = 1.78, rounding to 16:9


Display Resolution Aspect Ratio
1920*1440 pixels 4:3 (1.33)
1280*960 pixels 4:3 (1.33)
800*600 pixels 4:3 (1.33)
640*480 pixels 4:3 (1.33)
1920*1200 pixels 16:10 (1.6)
1440*900 pixels 16:10 (1.6)
1280*800 pixels 16:10 (1.6)
1920*1080 pixels 16:9 (1.78)
1280*720 pixels 16:9 (1.78)
640*360 pixels 16:9 (1.78)


If you don't know the exact resolution but know the approximate monitor size, you can also compare the width vs height in inches to determine the aspect ratio.

Finally, you can simply refer to common preset aspect ratios if you know the general device type:

  • TVs and computer monitors are typically 16:9
  • Older TVs and monitors often used 4:3
  • Newer desktop monitors now use 16:10 more commonly
  • Most phones and tablets are 16:9 or taller ratios like 9:16

By dividing the resolution, comparing dimensions, or checking preset ratios, you can easily determine the aspect ratio of any display.


    Adjusting Aspect Ratios

    When using multiple displays with different aspect ratios, like a laptop monitor and an external monitor, some adjustment may be required to get the best visual experience. The aspect ratio settings can be changed in the display settings menu.

    Select the external display and you can change the resolution to match the aspect ratio you want. Lower resolutions will have a more stretched or condensed look, while higher resolutions will look sharper and have less distortion.

    You may need to experiment with different resolutions to find the right balance of visual quality without black bars or stretching on that display. The laptop monitor resolution likely won't need adjustment if it matches your desired aspect ratio already.


    Windows 10 / Windows 11 Display Settings

    Right click on the desktop and select "Display Settings" to bring up the display configuration window. In this window, you can set the aspect ratio by changing the display resolution. Any external monitors connected will show up as additional monitors that can be configured separately.

    Windows Aspect Ratio Setting


    MacOS Display Setting

    Click the “System Preferences” menu, you can set the aspect ratio by changing the display resolution.

    MacOS Aspect Ratio Setting


    Aspect Ratios in Kefeya Portable Laptop Monitor Extender

    Portable displays like laptops and external monitors often have default aspect ratios configured. For example, most Kefeya portable monitor utilize a 16:9 aspect ratio by default.

    Kefeya newer models, the Z1 stacked monitor extender and the Q2 metal-shell monitor extender, have adopted a 16:10 aspect ratio configuration instead. The slightly more vertical 16:10 ratio provides a bit more height for productivity apps and web browsing. 

    Kefeya Z1 Stacked Portable Monitor Extender

    Kefeya Z1 Stacked Portable Monitor Extender


    Kefeya Q2 Metal-shell Portable Monitor Extender

    Kefeya Q2 Metal shell Portable Monitor Extender



    Aspect ratios play an important role in determining how content is displayed across different types of monitors and devices.

    Understanding aspect ratios allows you to get the most out of your displays. Matching aspect ratios properly gives you the best viewing experience and allows visual media to be presented as originally intended. Hope the knowledge provided in this guide, can help you correctly manage aspect ratios across your devices.