What Is Aspect Ratio? (16:9, 21:9, 4:3)

The aspect ratio is the ratio between the width and height of the screen. Find out what 16:9, 21:9 and 4:3 mean and which one you should pick.


The aspect ratio is the ratio between the width and height of the screen. It’s noted in the form of W:H, which is interpreted as pixels in width for every H pixel in height.

When buying a new PC monitor or perhaps a TV screen, you’ll stumble on the specification called “Aspect Ratio.” Wondering what this means?

This is essentially just the ratio between the width and height of the display. The higher the first number compared to the last number, the wider the screen will be compared to the height.

Most monitors and TVs today have an aspect ratio of 16:9 (Widescreen), and we are seeing more and more gaming monitors getting a 21:9 aspect ratio, also referred to as UltraWide.

There are also several monitors with a 32:9 aspect ratio, or ‘Super UltraWide.’

Other, less popular, aspect ratios are 4:3 and 16:10, though finding new monitors with these aspect ratios is difficult nowadays, they were quite widespread back in the day.

List Of Popular Aspect Ratios And Screen Resolutions

4x3 vs 16x9 vs 21x9 1
21:9 and 4:3 content displayed on a 16:9 display

Here’s a list of aspect ratios and associated screen resolutions:

  • 32:9 aspect ratio: 3840×1080, 5120×1440, 7680×2160
  • 21:9 aspect ratio: 2560×1080, 3440×1440, 3840×1600, 5120×2160
  • 16:9 aspect ratio: 1280×720, 1366×768, 1600×900, 1920×1080, 2560×1440, 3840×2160, 5120×2880, 7680×4320
  • 16:10 aspect ratio: 1280×800, 1920×1200, 2560×1600
  • 4:3 aspect ratio: 1400×1050, 1440×1080, 1600×1200, 1920×1440, 2048×1536

What Aspect Ratio Should I Use?

What Is Aspect Ratio
Click to enlarge

Most of the time, the best aspect ratio will be whatever your display’s native screen resolution/aspect ratio is. However, it also depends on what type of content you are watching as well as your personal preference.

16:9 is the most widespread aspect ratio as it is used for the most common monitor and TV resolutions, including 1920×1080 and 4K. Moreover, a 16:9 aspect ratio is very versatile as it can decently display both 4:3 and 21:9 content.

When it comes to gaming, ultrawide monitors can offer massive benefits due to the broader field of view. That’s why some competitive games will limit the aspect ratio to 16:9, meaning you’ll have black bars at the sides of the screen.

In the end, you should use whatever aspect ratio you see fit!

You Might Love These Too

What Is G Sync
What Is G-SYNC And What Does It Do?
Rob Shafer

Rob is a software engineer with a Bachelor’s degree from the University of Denver. He now works full-time managing DisplayNinja while coding his own projects on the side.