Video Aspect Ratios Explained: 9:16, 16:9, 1:1, 4:5

A video's aspect ratio is the relationship between its width and height, written as width:height. 16:9 is the standard horizontal shape for YouTube and TVs, 9:16 is the vertical shape for Reels, Shorts and TikTok, 1:1 is square, and 4:5 is the slightly tall shape that fills more of an Instagram or Facebook feed. Pick the ratio for where the video will be watched, then export at the matching resolution, such as 1920x1080 for 16:9 or 1080x1920 for 9:16.

What aspect ratio actually means

Aspect ratio is a shape, not a size. A 16:9 video can be tiny (640x360) or huge (3840x2160); both have the same proportions. Resolution is the number of pixels; aspect ratio is how those pixels are arranged.

You can work out the ratio by dividing both numbers by their greatest common factor. 1920x1080 divided by 120 gives 16x9. 1080x1350 divided by 270 gives 4x5. Simple as that.

Common ratios and resolutions

For most creators, two ratios cover nearly all of the work: 16:9 for long-form and 9:16 for short-form.

Which platform uses what

Platforms adjust their specs over time, so confirm on each platform's help pages before a big campaign. As a general guide:

• YouTube (long-form): 16:9. Other ratios play with black bars or are adapted by the player.
• YouTube Shorts: 9:16 vertical (square is accepted).
• Instagram Reels: 9:16. The grid shows a cropped cover, so keep your subject centered.
• Instagram feed: 4:5 is the tallest commonly used shape for feed posts; 1:1 and horizontal also work but take less space.
• TikTok: 9:16.
• Facebook: 9:16 for Reels and Stories, 4:5 or 1:1 for feed, 16:9 for longer videos.
• LinkedIn: 16:9, 1:1 and 4:5 all appear in feeds; vertical is increasingly common.

If you're deciding which shape to shoot, our article on vertical vs horizontal video covers the strategic choice.

Converting between ratios

Converting means either cutting something off or adding something. There are four main approaches:

1. Crop

Cut away the parts of the frame that don't fit. Going from 16:9 to 9:16 keeps only about a third of the original width. It works well for a single speaker in the middle of the frame and badly for wide scenes, slides or two people far apart. Following the subject as they move is called reframing; see auto reframe explained.

2. Letterbox or pillarbox

Fit the whole frame inside the new shape and fill the empty space with bars, a blurred copy of the video, or a branded background. Nothing is lost, but the actual content gets small. Fine for a quick share; weak for content designed to stop the scroll.

3. Rebuild the layout

Rearrange elements for the new shape: speaker in the top half, a graphic or screen recording in the bottom half, headline at the top. More work, much better result, especially for tutorials.

4. Re-edit for the format

Sometimes the right conversion is a new edit. A vertical version can use different pacing, bigger captions and different visuals. Tools that output both orientations from the same raw clip help here: ShotFlick, for example, can produce a vertical (9:16) or horizontal (16:9) edit of the same talking-head video.

Resolution tip

Cropping throws away pixels. A 9:16 crop from 1080p horizontal footage is only about 608 pixels wide before it's scaled up to 1080. It's usually acceptable on a phone but noticeably softer. If you know you'll need both shapes, record in 4K, or shoot vertically and plan your horizontal version around it.

Posting one video everywhere

If you publish the same content on several platforms, choose your master format first:

• Mostly short-form: record and edit in 9:16. It covers Reels, Shorts and TikTok, and works in Stories. For feeds that prefer 4:5, a centered crop of a vertical video usually works if you kept your subject and text in the middle.
• Mostly YouTube long-form: record in 16:9, ideally 4K, so you can crop vertical clips later without losing too much detail.
• Both equally: consider editing two versions from the same raw recording rather than converting one finished edit, because text, captions and visuals need different placement in each shape.

Safe zones

The full frame isn't always visible or uncovered. A safe zone is the area where you can put important content (faces, text, captions) and trust it won't be hidden.

• Vertical short-form: the bottom part of the screen holds the caption, username and audio info; the right edge holds like, comment and share buttons; the top has a few app controls. Keep key content in the central area, with faces in the upper-middle.
• Feed crops: a 9:16 Reel may appear cropped to a shorter shape on the profile grid or in some feeds. Keep the subject near the center so the crop still works.
• Horizontal video: keep text a comfortable distance from the edges, and leave the bottom area clear where player controls and captions appear.

Exact margins differ per app and change with redesigns. A practical method: export a test frame, upload it as a draft or private post, and look at it on your phone with the interface showing.

Checking your framing before you record

The cheapest way to handle aspect ratios is to plan for them at the camera. If you know a video will be published both as a 16:9 upload and as 9:16 clips, frame yourself slightly wider than usual and keep your head and hands near the centre of the shot. That leaves room to crop to vertical later without cutting off your face or your gestures.

Before a long recording, shoot ten seconds, then crop that test clip to every ratio you plan to use. Look for anything important near the edges: a product you hold up, text on a whiteboard, or a second person in the frame. Moving the camera a few centimetres now is far easier than trying to rescue a shot in the edit, and it means automatic reframing tools have a clean, centred subject to work with.