Understanding Video Aspect Ratios: From Cinematic to Vertical

Aspect ratio is one of those things you don't think about until something looks wrong. Black bars where there shouldn't be any, or important parts of your video getting cut off. Let's demystify what these numbers actually mean.

What Is an Aspect Ratio?

An aspect ratio describes the relationship between a video's width and height. When you see "16:9," it means for every 16 units of width, there are 9 units of height. The actual size doesn't matter—a 16:9 video could be 1920x1080 pixels or 3840x2160 pixels. What matters is the shape.

Think of it like a picture frame. A 16:9 frame is always a wide rectangle, whether it's the size of your phone screen or a movie theater.

The Common Ratios

16:9 — The Standard Widescreen

This is what most people mean when they say "widescreen." It's been the default for YouTube, computer monitors, and most TVs since the mid-2000s. If you're filming with your phone held horizontally, you're probably shooting 16:9.

9:16 — Vertical Video

Take 16:9 and rotate it 90 degrees. That's 9:16, and it's everywhere now thanks to smartphones and social media. TikTok, Instagram Reels, YouTube Shorts, Snapchat—they all use this format because that's how most people hold their phones.

1:1 — The Square

Equal width and height. Instagram popularized this format, though they've since moved on to supporting other ratios. Square video still works well for content that needs to look good both on mobile and desktop, or when you want a balanced, neutral composition.

4:5 — Portrait

A subtle vertical format that's taller than it is wide, but not as extreme as 9:16. Instagram supports this for feed posts, and it's nice because it takes up more screen space than 1:1 while still fitting comfortably in a scrolling feed.

4:3 — The Old Standard

This was the standard before widescreen took over. Old TVs, early computer monitors, and many webcams still use 4:3. It's slightly wider than it is tall—a stubby rectangle. You'll still see it in some contexts, but it's largely been replaced by 16:9.

21:9 — Ultrawide / Cinematic

Even wider than 16:9, this is what you see in many movies. It creates that "cinematic" look with black bars at the top and bottom when viewed on a 16:9 screen. Some filmmakers and content creators use it for aesthetic reasons.

Why Does This Matter?

When your video's aspect ratio doesn't match where you're posting it, something has to give. Either:

• •Black bars appear (letterboxing or pillarboxing) to fill the extra space
• •Parts get cropped off to make the video fit
• •The video gets stretched (looks awful, avoid this)

The first two are common and sometimes unavoidable. Stretching is never acceptable—people and objects will look distorted and wrong.

Converting Between Aspect Ratios

If you've shot in one ratio and need another, you'll have to crop. This means deciding what part of the original frame to keep. With a tool that lets you position the crop region, you can focus on the most important part of each shot.

Going from horizontal to vertical loses a lot of width. Going from vertical to horizontal loses a lot of height. There's no way around this—cropping always means sacrificing part of the image.

A Visual Comparison

Here's how the common ratios compare to each other when scaled to the same width:

Wrapping Up

Aspect ratios aren't complicated once you understand what they represent. The key things to remember: 16:9 for standard video, 9:16 for vertical social content, and always crop rather than stretch.

Need to change your video's aspect ratio? Our cropping tool makes it easy to select a preset ratio and position the crop exactly where you want it.