Guide
9:16 means nine units wide for every sixteen tall. The phone screen, written as a fraction
An aspect ratio of 9:16 means the frame is nine units wide for every sixteen units tall. It is the vertical mirror of 16:9 television, and at full HD it measures 1080 pixels wide by 1920 tall. Every major short-form feed displays this shape edge to edge. This page covers the arithmetic, the common sizes and what players do with every other shape.
- Width divided by height, the ratio as a decimal
- 0.5625
- The ratio at full HD
- 1080x1920
- The same rectangle, turned on its side
- 16:9
Width first, height second, and the order is the whole trick
An aspect ratio is always written width against height. So 9:16 is tall and 16:9 is wide, and they are the same rectangle rotated ninety degrees.
Mixing the two up is the most common export mistake in short-form video. The file plays either way, but one of them arrives in the feed as a shrunken sideways strip.
As a decimal, 9 divided by 16 is 0.5625. Any frame whose width is 56.25 percent of its height is a 9:16 frame, whatever its resolution.
Ratio is not resolution, and several sizes are all 9:16
720 by 1280, 1080 by 1920 and 2160 by 3840 are all exactly 9:16. Same shape, different amounts of detail.
That is why the answer to what size should I export has two parts. The ratio is fixed by the destination. The resolution is a choice, and 1080 by 1920 is the one the players are built around.
Check the arithmetic on any frame in one line. Divide the width by the height, and if the answer is 0.5625 the shape is right.
Width as a share of height, common frames
The lower the bar, the taller the shape. Only the first fills a phone screen edge to edge.
- 9:16 vertical56%
- 4:5 portrait80%
- 1:1 square100%
- 16:9 horizontal178%
This is the whole editor
Highlight a phrase and a clip lands on those exact words. No timeline, no keyframes, no layers.
What a player does with every other shape
A full-screen vertical player has two options for a file that is not 9:16. Shrink it until it fits and fill the rest with bars, or zoom it until it fills and crop what hangs over.
Both cost you something. Bars make the video feel small and borrowed. A zoom crops picture you composed, and it crops without asking which part mattered.
The only way to control what the viewer sees is to hand the player the shape it wants. Cutroom sidesteps the whole question by exporting 9:16 only.
Questions people ask
- Is 9:16 the same as 1080 by 1920?
- 1080 by 1920 is one resolution of the 9:16 ratio, and the standard one. 720 by 1280 and 2160 by 3840 are the same shape with less and more detail. Ratio is the shape, resolution is the pixel count.
- Why is it written 9:16 and not 16:9?
- Convention puts width first. A 9:16 frame is nine wide and sixteen tall, so it is vertical. Writing 16:9 describes the same rectangle lying on its side, which is television.
- Does 9:16 work on YouTube?
- As a Short, yes, natively and full screen. Uploaded as a regular video it plays in a horizontal player with heavy bars either side, which is legal and looks poor. The format is built for the Shorts shelf.
Divide the width by the height and aim for 0.5625. Every file Cutroom hands over is already that shape, because the destination only respects one.