Aspect ratios, explained once
16:9, 4:3, 2.39:1, 9:16, 4:5 — the numbers describe the shape of a frame, and mixing them is where black bars and cropped heads come from. Here is the whole idea in one place.
Every image and video has a shape, and the aspect ratio is how we describe it. It is a simple idea that causes a surprising amount of trouble, mostly because different screens, cameras and platforms each prefer a different one.
What the numbers mean
An aspect ratio is width : height. 16:9 means sixteen units wide for every nine units high, whatever the actual size. A 1920 × 1080 video is 16:9; so is 3840 × 2160, and so is 1280 × 720.
Sometimes the ratio is written as a single number — width divided by height. 16:9 is 1.78. The cinema ratios below are usually written that way.
Aspect ratio says nothing about resolution. A tiny 16:9 thumbnail and a 4K film share the same shape.
The common ones
16:9 (1.78) — the standard for television, computer screens, YouTube and most video today. It became the standard for HD television as a compromise between older TV and cinema shapes.
4:3 (1.33) — the shape of older television and early computer screens. Still common for iPad screens and many digital cameras' still photos.
3:2 (1.5) — the shape of 35 mm film and most DSLR and mirrorless camera photos.
1.85:1 and 2.39:1 — cinema. 2.39:1 is the very wide "scope" format used for many feature films.
1:1 — square. Once Instagram's only shape; still used for feeds and profile images.
4:5 (0.8) — a slightly tall rectangle. The tallest shape Instagram allows in the feed, and a common choice for feed posts because it takes up more screen.
9:16 (0.56) — 16:9 turned on its side. Phone-shaped. The shape of Stories, Reels, TikTok and Shorts.
When shapes don't match
A video in one shape shown on a screen of another has to be adapted, in one of three ways.
Fit (letterbox or pillarbox). Shrink the video until it fits entirely inside the frame, and fill the rest with bars. A wide film on a 16:9 TV gets bars above and below — letterboxing. A 4:3 video on a 16:9 screen gets bars on the sides — pillarboxing. Nothing is lost; some of the screen is empty.
Fill (crop). Enlarge the video until the frame is completely covered, and cut off whatever spills over. No bars, but part of the picture is lost — and it is enlarged, which can soften it.
Stretch. Force the video to the new shape by distorting it. Circles become ovals and people become wider or thinner. It is almost always wrong.
Most apps and platforms choose fit or fill for you. Knowing which lets you predict what the audience will see.
Phone video and rotation
A phone held upright records a 9:16 video. Usually the file itself is stored in landscape shape, with a rotation tag telling players to turn it upright. Most modern software respects the tag. Occasionally an older tool ignores it and the video appears on its side. Re-exporting from an editor that reads the tag fixes it permanently.
Choosing a ratio
The rule is simple: choose the ratio for where the video will mainly be watched, before you start editing.
- YouTube, websites, presentations, TV: 16:9.
- Instagram feed: 4:5, or 1:1.
- Stories, Reels, TikTok, Shorts: 9:16.
- A film with a cinematic look: 16:9 frame with a wider image inside, letterboxed — or a true wide ratio if the destination supports it.
If a video must work in several places, edit a version for each rather than relying on one to be adapted. A 16:9 edit cropped to 9:16 loses more than two-thirds of the picture, and the important part is not always in the centre. We covered reframing landscape footage for portrait feeds in more detail.
Shooting with ratios in mind
If you know the video will be cropped to different shapes, frame loosely and keep the important subject near the centre. Shooting at a higher resolution than you need — 4K for a 1080p output — leaves room to crop without softening.
For a single known destination, shoot in that shape. Phone video for a 9:16 platform is best shot upright.
Mixing ratios in one edit
Clips of different shapes in one project each need a decision:
- Fill the frame — crop — when the subject survives it.
- Fit with a background — bars, a blurred copy of the clip, or a solid colour — when it does not.
Be consistent. Alternating between cropped and letterboxed clips looks accidental.
What Garfi does
Garfi Video Editor sets the frame shape at the project level, with landscape, portrait, square and 4:5 canvas formats — the shapes above that most people publish in. Each clip can then be placed with fit or fill, cropped, rotated or flipped, so mixed-ratio footage is handled clip by clip rather than by one global rule.
Because projects are portable .gvideo packages, making a second version in another shape starts from the same edit. Export is MOV or MP4 in H.264 or HEVC, up to 4K when supported, with no watermark.
The download is free with an export trial you start yourself; a one-time purchase unlocks export permanently. Editing and saving projects remain available either way. There is no account, developer cloud or generative AI.