16:9 aspect ratio
16:9 is the widescreen standard for video and displays, with a decimal value of 1.7778. Every common HD resolution from 1280 by 720 upward sits on it exactly.
At a glance
- Ratio
- 16:9
- Decimal value
- 1.7778 (width divided by height)
- CSS aspect-ratio
- aspect-ratio: 16 / 9;
- Common pixel dimensions
- 1280 x 720, 1600 x 900, 1920 x 1080, 2560 x 1440, 3840 x 2160
- Suits
- Video, screen recordings, presentation slides and hero banners
- Struggles with
- Upright phone screens, print pages and profile grids
In detail
The ratio was chosen as a compromise rather than inherited from anything. When the high definition standard was being set, television was 4:3 at 1.33 and cinema ran from about 1.85 to 2.35, and the reasoning usually given is that 1.78 sits at the geometric mean of that range, so every existing format could be shown with the least total wasted area on one screen.
It has an unusually convenient property for a working ratio: an enormous number of round pixel dimensions land on it exactly. 720, 900, 1080, 1440 and 2160 are all whole multiples of nine that pair with whole multiples of sixteen, so an entire resolution ladder exists with no rounding at any step and no crop between rungs.
That makes it the safest default for anything that will be embedded, downscaled or shown on a screen you do not control. A single 16:9 master feeds a video player, a slide deck, a documentation screenshot and a thumbnail without a ratio decision at any point.
It is a poor choice for a phone held upright, where it becomes a narrow band with most of the screen unused, and for print, where nothing in the A series or the letter family is anywhere near 1.78. Those are the two cases where a 16:9 asset library forces either bars or a crop on everything.
Examples
1280 x 720 0.92 MP
1600 x 900 1.44 MP
1920 x 1080 2.07 MP
2560 x 1440 3.69 MP
3840 x 2160 8.29 MP
// every step divides to 16:9 with no remainder.embed {
aspect-ratio: 16 / 9;
width: 100%;
background: #111;
}The box is the right shape before the media loads, so nothing below it shifts.
Things that catch people out
- 16:9 at 1.78 and the 1.91:1 used by link preview cards are close enough to look interchangeable and different enough to crop. They are not the same shape.
- A 16:9 hero image on a phone in portrait is a thin strip. Art direct a second crop rather than scaling the same file down.
- Rounding a width that is not a multiple of sixteen gives a height that is off by a pixel, which shows as a hairline gap in a tiled layout.
Try it: Aspect Ratio Calculator
Enter a width and a height, or a ratio and one dimension, and it solves the missing one, simplifies the ratio, counts the megapixels and gives you a copyable CSS value.
Aspect Ratio Calculator
LOCAL · Browser-OnlyCalculate and convert aspect ratios for images, videos, and screens
1920 x 1080px · 16:9 · 1.7778:1
Common Aspect Ratios Reference
| Ratio | Decimal | Common Use |
|---|---|---|
| 16:9 | 1.778 | Widescreen TV, YouTube, monitors |
| 4:3 | 1.333 | Classic TV, iPad, presentations |
| 1:1 | 1.000 | Instagram square, profile pictures |
| 21:9 | 2.333 | Ultrawide monitors, cinema |
| 9:16 | 0.563 | Phone vertical, TikTok, Reels |
| 3:2 | 1.500 | 35mm photography, MacBook |
| 2:3 | 0.667 | Portrait photography, posters |
| 5:4 | 1.250 | Large format photography, older monitors |
| 32:9 | 3.556 | Super ultrawide monitors |
| 2.39:1 | 2.390 | Anamorphic cinema, widescreen films |
Related Image and canvas sizes
All image and canvas sizes →4:3 aspect ratio
The 1.333 ratio that ran television and computer monitors for decades, where it still appears today, and how it compares to the widescreen shapes.
21:9 aspect ratio
The 21:9 marketing label at 2.3333, the 43:18 and 64:27 shapes that real ultrawide panels actually use, and how to design for the gap between them.
9:16 aspect ratio
The vertical video ratio at 0.5625, its exact inverse relationship with widescreen, and why modern phone screens are taller than it.
1:1 aspect ratio
The square ratio, its origins in medium format film and social feeds, why it is the most reusable shape, and where it wastes space.
3:2 aspect ratio
The 1.5 ratio inherited from the 35mm film frame, the sensors and laptop screens that still use it, and how it sits between 4:3 and 16:9.
2:3 aspect ratio
The portrait form of the 35mm frame at 0.6667, why it is the recommended shape in masonry feeds, and how it compares to 4:5 and 9:16.
Tools for this
- Aspect Ratio Calculator Free online aspect ratio calculator - calculate and convert aspect ratios for images, videos, and screens
- Image Cropper Free online image cropper - crop images with preset aspect ratios and free-form selection