Aspect ratio

What is it?

Aspect ratio is a physical characteristic of a screen, whether it’s on a PC monitor, a laptop or a TV. It refers to the relationship between the width and the height of the screen, usually stated as two numbers, separated by a colon. The first number refers to the width of the screen, the second to the height.

How does it work?

The numbers aren’t actual measurements in millimetres or inches, but refer to their respective lengths relative to each other. For example, TV screens used to have an aspect ratio of 4:3 (pronounced “four by three”), which is a squarish rectangle that’s 33 per cent wider than it is tall. Modern TVS are usually 16:9 (“sixteen by nine”), which has been popular since the introduction of widescreen TVS.

What are the specs?

16:9 is the most common aspect ratio you’ll come across, though some monitors and laptops still have the older, squarer 4:3 screens. There are also ‘ultra-wide’ screens with aspect ratios of 21:9 (these are strictly speaking 64:27 but the values are rounded down to keep them more easily comparable with 16:9).

There are other aspect rations, but they’re relatively rare, but comparing them to these three will give you an idea of how wide they are.

Although the resolution of a screen is dependent on its aspect ratio, you can still get different resolutions within each ratio. For example, 1920x1080 pixels (1080p) and 3840x2160 pixels (4K) both have an aspect ratio of 16:9.

Can I change it later?

No, the aspect ratio is a physical characteristic of the screen, so can’t be changed or upgraded.