What is an Aspect Ratio? Understanding and Common Aspect Ratios

If you’ve ever watched a video with black bars on the side or found your footage awkwardly cropped on a screen, you’ve encountered the challenge of mismatched aspect ratios.

In a world full of screens—widescreen TVs, vertical smartphone displays, cinematic monitors, and social media feeds—understanding aspect ratios is more important than ever. This article explores the most common aspect ratios used in video production and display today, how they relate to resolution, and how to choose the right one for your content or device.

In this guide, we’ll demystify common and not-so-common aspect ratios, explain how they relate to screen resolutions, and help you decide which aspect ratio best suits your use case—be it YouTube videos, HD TV, or vertical social media content.

Table of Contents

1. What is the video aspect ratio?
2. Common aspect ratios
3. Aspect ratio and resolution
4. Best aspect ratios for social media videos
5. What is the best aspect ratio for your video?
6. How to change the aspect ratio of a video?
7. Final thought

What is the video aspect ratio?

An aspect ratio describes the proportional relationship between a screen’s width and height. It is written as a ratio like 16:9 or 4:3, where the first number represents the width and the second the height.

Aspect ratio does not measure size or resolution directly. Instead, it defines the shape of the video or screen.

For example:

• A 16:9 video might be 1920 pixels wide by 1080 pixels tall (1920×1080).
• A 4:3 video could be 1024×768.
• A 1:1 video would be a perfect square, such as 1080×1080.

This simple ratio has a big impact on how content is captured, edited, displayed, and consumed.

Common aspect ratios and their use cases

Video aspect ratios have evolved over the past few years with the diversification of devices. The most common aspect ratio for video content on the web is 16:9 for widescreen display, 1:1 for square display, and 9:16 for vertical display.

Let’s explore the different aspect ratios for video creation.

16:9 – the widescreen standard

Today’s dominant format, 16:9 (also written as 16x9 or 16.9), is considered the standard aspect ratio for most digital video content. It is the native format for HD and Full HD resolutions, and is used across:

• Television broadcasts
• Computer monitors
• Online video platforms (YouTube, Vimeo)
• Video conferencing software
• Gaming consoles and streaming devices

Resolution examples:

• 1280×720 (HD)
• 1920×1080 (Full HD)
• 3840×2160 (4K UHD)

In pixels: 16x9 aspect ratio in pixels means the width is 1.78 times the height. For example, 1920 by 1080 pixels.

To accommodate HD format video, new monitors and laptops are generally manufactured with a 16:9 aspect ratio. This ensures content appears full screen without letterboxing or stretching.

4:3 – the classic fullscreen format

Before widescreen became the norm, 4:3 was the standard screen format for analogue televisions and early computer displays.

Still used in:

• Archival video content
• Old TV shows and films
• Classic presentations

Resolution example: 1024×768

Though largely replaced by widescreen, some educational platforms and video conferencing setups still support 4:3 for compatibility.

1:1 – square aspect ratio

A perfectly square frame, 1:1, is widely used in social media platforms like Instagram.

Use cases:

• Profile videos
• Thumbnails
• Platform-native video creation

In pixels: Common resolutions include 1080×1080 or 1200×1200.

1:1 offers simplicity, particularly in environments where uniformity across different devices is desirable.

9:16 – vertical video

The vertical counterpart to 16:9, this portrait-oriented aspect ratio (often written as 9:16) dominates mobile-first platforms like TikTok, Instagram Reels, and YouTube Shorts.

Typical resolution: 1080×1920

9:16 aspect ratio in pixels essentially flips the Full HD resolution on its side, favouring smartphones held upright.

21:9 and beyond – ultra-widescreen

Often referred to as cinematic or anamorphic widescreen, ultra-wide formats such as 21:9 are designed for immersive viewing experiences.

Used in:

• Cinematic film production
• High-end gaming
• Ultra-wide monitors

Examples:

• 2560×1080 (Full HD ultra-wide)

• 3440×1440 (WQHD ultra-wide)

• 4096×2160 (DCI 4K)

These formats may not be widely supported across all devices, but are essential in high-production settings and enthusiast setups.

So, what is an anamorphic widescreen?

Anamorphic widescreen is a picture on standard 35 mm with a non-widescreen native aspect ratio. It can be displayed by a 2.39:1 aspect ratio. However, when displayed on a 16:9 screen, you’ll notice black bars on the top and bottom that accommodate a wider field of view of the display screen.

Aspect ratio and resolution

A common confusion arises between aspect ratio and resolution.

• Aspect ratio refers to the shape: the ratio of width to height.
• Resolution refers to the total number of pixels: e.g., 1920×1080.

While two screens can have the same aspect ratio, their resolutions can vary significantly depending on pixel density and screen size.

1920 x 1080 (Full HD): crystal-clear detail

This resolution packs 1920 pixels horisontally and 1080 pixels vertically in a 16:9 ratio. It's a baseline for quality, offering clear visuals for various platforms. By default, smartphones, DSLRs, and modern camcorders record videos at 1920 by 1080.

3840 x 2160 (UHD): ultra clarity

Next, we have 3840 x 2160, also called Ultra HD (UHD) or 4K UHD. This resolution displays incredibly sharp visuals best suited for large screens, 16:9 widescreens and interactive screens.

4096 x 2160 (4K UHD): cinematic precision

Lastly, we have 4096 x 2160, or the cinematic 4K UHD resolution, which in most cases has a 1.90:1 aspect ratio. It’s widely used for filmmaking since it captures the small and intricate details and vivid colours, making the video content visually appealing.

Best aspect ratios for social media videos

The optimal video ratio sizes for video content on social media platforms vary according to each platform's guidelines. Sticking to their recommended aspect ratios guarantees your video appears flawlessly within their player interface.

As illustrated in the table above, different social media platforms offer various video aspect ratio sizes. To ensure that you provide your audience with enhanced visual appeal, it’s important to experiment with different ratio aspects to make sure your video content works well with the social media platform you choose. Adopting this approach can also help to align better with your social media branding goals.

What is the best aspect ratio for your video? 

16:9 is the most popular and common video aspect ratio, but it’s not a “one-size-fits-all” case when it comes to choosing a video aspect ratio. Different platforms offer flexible aspect ratios that allow you to configure the aspect ratio to match the type of video content you want to share.

 As such, although 16:9 aligns with HD TVs and major streaming platforms like YouTube, Netflix and TikTok, the “best” aspect ratio varies. To determine the optimal aspect ratio for your content, think about its intention and broadcast platform.

Factors to consider when choosing an aspect ratio

Selecting the perfect aspect ratio harmonises your message with its medium, ensuring your video resonates with viewers across their preferred platforms and devices.

How aspect ratios affect video production and display

Video editing and export

Understanding the target aspect ratio ensures your content is displayed properly across different devices and platforms. Exporting a video in 16:9 ensures compatibility with most platforms. Cropping a 16:9 video into 1:1 or 9:16 can lose important content if not planned from the start.

Live streaming and conferencing

Most live video tools—including Digital Samba—use 16:9 or adapt dynamically to user devices. HD video aspect ratio support ensures consistent quality while allowing flexible display on different screens.

Screen design and monitor choice

Choosing the best monitor aspect ratio depends on usage:

• 16:9: best for everyday work, video watching, and gaming
• 21:9 or 32:9: best for multi-tasking or cinematic experiences
• 4:3 or 5:4: niche use or legacy support

How to change the aspect ratio of a video?

In the realm of video production, aspect ratio holds immense importance. But altering it post-filming presents challenges. Two methods exist: adding black bars or cropping.

1. Cropping, precision challenge: While possible, post-filming alterations have downsides. Cropping, requiring capable video editing software, risks omitting vital elements.
2. Adding black bars, aesthetic compromise: Alternatively, black bars maintain video integrity but sacrifice aesthetics.
3. Tools for aspect ratio transformation. Consider these tools:

• Professional video editors: Adobe Premiere Pro and Final Cut Pro offer control.
• Free and open-source alternatives: Blender and Shotcut suit budget-conscious creators.
• Online converters: Quick fixes via online video converters and compressors.

Remember, the right aspect ratio ensures your video's message resonates. Broadcasting platforms often auto-adjust aspect ratios – YouTube's 16:9, for instance.

Final thought

As we wrap up our exploration of video aspect ratios, let's delve deeper into their technical impact on video production. Embracing diversity in aspect ratios and resolutions offers you a canvas of innovation to experiment and enhance your content's visual narrative.

When it comes to Digital Samba, the intricacies of aspect ratios vary across platforms and devices. The adaptable nature of these ratios, such as the standard video aspect ratio, 16:9 and traditional 4:3, underscores the importance of compatibility.

For video conference participants seeking precision, Digital Samba's VPaaS tailored approach ensures your content resonates flawlessly with the platform or device you’re using. It's more than just ratios; it's about making technology work seamlessly for your creative vision. 

Frequently asked questions

What is the aspect ratio of 1920x1080?

It is 16:9, also known as Full HD.

What is the widescreen aspect ratio?

Typically 16:9, though cinematic formats use wider ratios like 21:9.

What is the full HD ratio?

1920×1080 resolution, which has a 16:9 aspect ratio.

What are the most common aspect ratios?

16:9 (modern standard), 4:3 (legacy), 1:1 (social), and 9:16 (mobile vertical video).

How can I determine the aspect ratio of a resolution?

Divide the width by the height. For example, 1920 ÷ 1080 = 1.78, which equals 16:9.