Aspect Ratio: What It Is and Why It Matters

Last Updated: December 14, 2021By

Black flat screen tv on white wall

Aspect ratios are everywhere. From TV screens to magazine pages, aspect ratios can be found in almost any media. Aspect ratio is the relationship between the width and height of an image or object, or in other words, how wide something is versus how tall it is.

There are multiple different types of aspect ratios, including things like 4:3, which means that a TV screen has a width that’s four times as wide as its height (a 16:9 TV would be 1.77:1). In this article, we will cover more on what aspect ratio is and why it matters.

What Is an Aspect Ratio and What Does It Do?

At its most basic, an aspect ratio is a relationship between two image dimensions. It’s expressed as width divided by height, and it can be found in any digital image you look at.

You might see it when you’re cropping or resizing a photo for Instagram or some other social media site; the app will tell you what the new aspect ratio is for your image so you can get it to fit better.

The aspect ratio of a TV screen, for example, is 16:9. This means that the screen is 16 units wide for every nine units tall. The most common aspect ratio for TVs used to be (and sometimes still is) called “standard definition” or SDTV, which has an aspect ratio of 4:3.

But what’s the point of knowing all this? Why do we even need to worry about aspect ratios? The answer has to do with how our eyes process information.

When it comes to TVs, movies, and other digital images, humans perceive width more acutely than height. In fact, for a long time, TV manufacturers took advantage of this by letterboxing movies and other content that was in a different aspect ratio than their screens.

These are the black bars you see at the top and bottom of a movie when it’s playing on a widescreen TV. It fills up more of your screen, but it’s not actually the correct aspect ratio for the image.

Now that more and more people are watching content on their phones and other devices that don’t have a 16:9 aspect ratio, letterboxing has become less common. But you’ll still see it sometimes, especially when someone is trying to watch a movie or TV show in a format that’s not supported by their device.

Why Does Aspect Ratio Matter?

Black flat screen tv turned on on wooden table

Aspect ratios are very important in many different things like TVs, magazines, and other media.

If you’re making content that’s meant specifically for certain screens or devices – social media posts on phones, digital art projects in apps designed only for mobile/tablet use, video editing programs where your goal is to make everything fit a certain aspect ratio – then using the wrong aspect ratio can lead to some pretty big problems.

For example, if you’re working on a project that’s designed for a 16:9 aspect ratio and you try to view it on an old TV that only supports an SDTV aspect ratio of, say, 4:3, the image will be letterboxed.

The same thing goes in reverse – if you have content that’s designed for a square pixel aspect ratio and try to watch it on a widescreen TV, you’ll get letterboxing.

This happens because images and videos with a different aspect ratio are “cropped” to fit the new ratio, and sometimes important information is lost in the process.

It’s not just about making sure everything looks good on different screens, either. Different aspect ratios can also affect how people interact with your content.

For example, a square video takes up more screen space than a traditional widescreen video, so it’s great for Instagram and other social media platforms where people are used to seeing square content.

Aspect ratios may seem like a small detail, but they can make a big difference in how your content looks and how people interact with it. Pay attention to them, and you’ll be able to create content that looks great no matter where it’s displayed.

When Should You Use a Different Type of Aspect Ratio for Your Project?

There are a lot of different reasons to use an aspect ratio other than the standard screen ratios. Here are some examples:

  • You’re creating digital art and want your project to fit perfectly on mobile devices like tablets or phones.
  • You’re creating a video and want to make sure it’s the correct aspect ratio for social media platforms like Instagram, Facebook, or YouTube.
  • You’re creating a digital project for another device, like a TV or some kind of gaming console.
  • You’re creating a presentation and want to be certain that your ideas and graphics take up the majority of the screen.

As you can see, there are a lot of different reasons to use an alternate aspect ratio. But it’s important to be mindful of the implications that using a different ratio can have on your project.

If you’re not sure which aspect ratio is right for your needs, do some research or ask someone for help. The last thing you want is to spend hours working on a project that you’re not happy with because the aspect ratio was wrong.

Aspect Ratio Examples

  • 16:9: The image is wider than it is tall. This is perfect for screens that have a 16:9 aspect ratio, like most modern TVs and Youtube videos.
  • 1:1: Both dimensions are equal in size, which makes this image perfectly fit into other squares (like Instagram posts) without any cropping.
  • 21:9: This is the aspect ratio for most widescreen movies.

What Is the Difference Between Aspect Ratio and Resolution?

Aspect ratio tells you the width to height ratio.

Resolution refers to how many pixels are in an image – 1080p is a higher resolution than 720p, for example. This means that a video in 1080 will look crisper and more detailed when compared with one at 720.

The same applies to images or other content where screen real estate is important. So, when you’re trying to decide on what resolution to export your project at, you’ll also want to take the aspect ratio into account.

What Happens When You Change Aspect Ratios?

When you change an image’s or video’s aspect ratio, sometimes part of the image is cropped out in order to fit into the new ratio. This can be a little bit jarring if you’re not expecting it, and it’s important to be aware of how this change will affect the overall look of your project.


Aspect ratio is a critical factor in creating content that looks great on different screens. By understanding the different types of aspect ratios and when to use them, you’ll be able to create projects with a more unified look and feel. Pay attention to the resolution as well – it’s important to choose the right one for your needs!