Video Aspect Ratios Explained: 9:16, 1:1, 4:5 and 16:9
You save a video, post it elsewhere, and it suddenly has black bars or the top of someone’s head is cut off. The culprit is the aspect ratio: the shape of the frame.
What an aspect ratio is
It is the width compared with the height. A 16:9 video is 16 units wide for every 9 units tall, so it is a wide rectangle. Flip it and you get 9:16, a tall rectangle that fills a phone held upright.
The shapes you will meet
| Ratio | Shape | Typical size | Used for |
|---|---|---|---|
| 9:16 | Tall | 1080×1920 | Reels, stories, short vertical video |
| 4:5 | Slightly tall | 1080×1350 | Instagram and Facebook feed posts |
| 1:1 | Square | 1080×1080 | Feed posts, profile grids |
| 16:9 | Wide | 1920×1080 | TV, laptops, landscape video |
Why black bars appear
When the video’s shape does not match the screen or the slot it is placed in, the player has two choices: shrink the video and fill the gaps with bars, or zoom in and crop the edges. Neither changes your file. It is only how that player displays it.
Choosing a shape when you post
- Reels and stories: 9:16. Anything else leaves empty space.
- Feed posts: 4:5 takes up more of the screen than square and far more than wide video.
- Watching on a TV or computer: 16:9.
Converting between shapes
Most phone editors have a crop or canvas tool. When turning a wide video into a tall one, you can crop to the important part of the frame, or keep the full picture and add a blurred or plain background. Keep faces and captions away from the top and bottom edges, where apps place buttons and text.
Does a downloaded video keep its shape?
Yes. A download is a copy of the file as the platform stores it, in the same shape and resolution.