What width is 2160 tall at 16:9?

2160 x 16 / 9 = 3840px. Use aspect-ratio: 16 / 9.

How to keep 2160 tall from stretching?

Set height: 2160px paired with the computed width, and aspect-ratio: W / H on the container; use object-fit for inner media.

2160 at this size works vertical or horizontal depending on ratio - check the table for portrait inversions like 9:16.

A 2160px-tall frame is used in many layouts. The table below lists the exact partner width at every ratio RatioCalc supports.

Ratio	Width for 2160	Pair	CSS
16:9	3840px	3840x2160	aspect-ratio: 16 / 9
4:3	2880px	2880x2160	aspect-ratio: 4 / 3
1:1	2160px	2160x2160	aspect-ratio: 1 / 1
9:16	1215px	1215x2160	aspect-ratio: 9 / 16
21:9	5040px	5040x2160	aspect-ratio: 21 / 9
3:2	3240px	3240x2160	aspect-ratio: 3 / 2
16:10	3456px	3456x2160	aspect-ratio: 16 / 10
4:5	1728px	1728x2160	aspect-ratio: 4 / 5
2:1	4320px	4320x2160	aspect-ratio: 2 / 1
239:100	5162px	5162x2160	aspect-ratio: 239 / 100
32:9	7680px	7680x2160	aspect-ratio: 32 / 9
5:4	2700px	2700x2160	aspect-ratio: 5 / 4
2:3	1440px	1440x2160	aspect-ratio: 2 / 3
18:9	4320px	4320x2160	aspect-ratio: 18 / 9
5:3	3600px	3600x2160	aspect-ratio: 5 / 3
1:2	1080px	1080x2160	aspect-ratio: 1 / 2

width = 2160 x rw / rh

// e.g. 9:16 at 2160 tall is 1215px

Vertical video at 2160 tall is 9:16 - 1215 wide; pair with aspect-ratio: 9 / 16.
Portrait feed at 2160 tall is 4:5 - 1728 wide.
Widescreen at 2160 tall is 16:9 - 3840 wide.

Print tip: at 2160px, verify with w = 2160 x rw / rh before print - 1px matters on narrow banners.